Using High-Efficiency PHY Frames for Motion Detection

ABSTRACT

In a general aspect, motion is detected in an environment using wireless signals. In one example, a downlink high-efficiency PHY (HE-PHY) frame is received. The downlink HE-PHY frame is transmitted by an access point device to wireless communication devices residing inside an environment. An uplink orthogonal frequency-division multiple access (UL-OFDMA) transmission is subsequently received in response to the downlink HE-PHY frame. The UL-OFDMA transmission is transmitted by the wireless communication devices to the access point device. The UL-OFDMA transmission includes uplink HE-PHY frames simultaneously transmitted on respective resource units by the respective wireless communication devices. A motion data set is generated based on channel responses computed from the uplink HE-PHY frames. Each channel response is computed from a respective one of the uplink HE-PHY frames. Motion within the environment is analyzed based on the motion data set.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 16/807,776, filed Mar. 3, 2020, entitled “UsingOver-the-Air Signals for Passive Motion Detection” the disclosure ofwhich is hereby incorporated by reference in their entirety.

BACKGROUND

The following description relates to using over-the-air signals forpassive motion detection.

Motion detection systems have been used to detect movement, for example,of objects in a room or an outdoor area. In some example motiondetection systems, infrared or optical sensors are used to detectmovement of objects in the sensor's field of view. Motion detectionsystems have been used in security systems, automated control systemsand other types of systems.

DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an example beamforming system including abeamformer and a beamformee.

FIGS. 2A to 2E show various examples of at least one listening deviceand a wireless communication network system.

FIGS. 3A to 3E show various examples of at least one listening deviceand an environment including a moving object.

FIG. 4 is a diagram showing received and observed wireless signals thatmay be used for extracting motion.

FIG. 5 show an example of a process that may be used to extract motiondata from wireless signals.

FIG. 6 is a diagram showing a flowchart for detecting motion in a remoteenvironment by a listening device.

FIG. 7 show an example of a process that may be used to extract motiondata from wireless signals.

FIG. 8 is a block diagram showing an example sensor device.

FIG. 9 shows an example of a physical (PHY) frame including a preamblecontaining training fields.

FIG. 10A is a diagram showing example downlink and uplink transmissionsin an example wireless communication network system.

FIG. 10B is a diagram showing example motion detection zones in anexample wireless communication network system.

FIG. 11A shows spectrum allocation in an example orthogonalfrequency-division multiplexing (OFDM) scheme.

FIG. 11B shows spectrum allocation in an example orthogonalfrequency-division multiple access (OFDMA) scheme.

FIG. 11C is a diagram showing an example sequence of HE-PHY framestransmitted in an example wireless communication network systemoperating according to the IEEE 802.11ax standard.

FIG. 11D is a diagram showing an example uplink-OFDMA transmission.

FIG. 12A shows an example HE-PHY frame having a High-EfficiencySingle-User PPDU (HE SU PPDU) format.

FIG. 12B shows an example HE-PHY frame having a High-EfficiencyTrigger-Based PPDU (HE TB PPDU) format.

FIG. 13A shows example resource unit allocations for a HE-PHY framehaving the HE TB PPDU format transmitted over a channel having abandwidth of 20 MHz.

FIG. 13B shows example resource unit allocations for a HE-PHY framehaving the HE TB PPDU format transmitted over a channel having abandwidth of 40 MHz.

FIG. 13C shows example resource unit allocations for a HE-PHY framehaving the HE TB PPDU format transmitted over a channel having abandwidth of 80 MHz.

FIG. 14 shows an example transmitter block diagram for the pre-HEmodulated fields of a HE-PHY frame having the HE TB PPDU format.

FIG. 15 shows an example format of a trigger frame.

FIG. 16 shows an example expansion of the frame control field of atrigger frame.

FIG. 17 shows an example expansion of the common information field of atrigger frame.

FIG. 18 shows an example expansion of the user information field of thetrigger frame.

FIG. 19 is a diagram showing a flowchart for an example process forcomputing channel responses in a wireless communication network systemoperating according to the IEEE 802.11ax standard.

FIG. 20 shows an example filter bank that can be used to equalizerespective HE-PHY frames.

FIG. 21 shows an example tuning of bandpass filters in the filter bankshown in FIG. 20.

FIG. 22 is a diagram showing a flowchart for an example process foranalyzing motion in an environment.

DETAILED DESCRIPTION

In some aspects of what is described, a wireless sensor device (e.g., alistening device) eavesdrops on over-the-air signals (e.g., wirelesssignals) exchanged between network devices in a space. In some cases,the over-the-air signals include either beamforming reports, physical(PHY) frames including preambles or training symbols, or both. In someinstances, the listening device is able to extract movement or motioninformation through examination of available over-the-air informationnormally exchanged by wireless devices communicating among each other.Motion may be detected based on the extracted movement or motioninformation. The listening device may obtain over-the-air informationexchanged between wireless devices without the listening device havingany association to the wireless network on which the over-the-airinformation is being exchanged. In this case, the over-the-airinformation may be used to sense motion of objects in a remoteenvironment, in a passive manner. In some cases, by examiningbeamforming dynamic information exchanged between devices, a motiondetection region may be constrained to the space or environment in whichthe communicating wireless devices reside. In some instances, thisallows the listening device to be placed anywhere within listening rangeof the communicating wireless devices.

The systems and techniques described here may provide one or moreadvantages in some instances. For example, the listening device mayprovide passive motion sensing so the motion detection may be performeddiscretely, e.g., by law enforcement, security, etc. Further, thelistening device may passively detect motion based on wirelesscommunication devices communicating using known protocols or processes(e.g., aspects of the IEEE 802.11 standard) implemented on commerciallyavailable wireless communication devices. In some instances, motion maybe detected within a geographically constrained sensing area regardlessof placement of the listening device.

In some aspects of what is described, over-the-air information isexchanged among wireless devices according to the IEEE 802.11axstandard. In the IEEE 802.11ax standard, a downlink transmission canoccur from an access point device to wireless devices associated withthe access point device. The downlink transmission can include aHigh-Efficiency Long Training Field” PHY frame, also known as HE-PHYframe, that is addressed to the wireless devices. The HE-PHY frame ofthe downlink transmission can include a trigger frame. The access pointdevice can allocate respective subsets of sub carriers, or resourceunits (RUs) to the respective wireless devices, and the trigger framecan include an indication of the resource unit allocation. The wirelessdevices transmit an uplink-orthogonal frequency-division multiple access(UL-OFDMA) transmission to the access point device in response toreceiving and processing the trigger frame. In the UL-OFDMAtransmission, the wireless devices transmit respective HE-PHY frames tothe access point device simultaneously using their respective subset ofsubcarriers. The listening device (or any other device) receiving thedownlink HE-PHY frame and the UL-OFDMA transmission can use thesetransmissions to sense motion of objects in an environment. The systemsand techniques described here may provide one or more advantages in someinstances. For example, since the UL-OFDMA transmission allows thewireless devices to transmit respective HE-PHY frames to the accesspoint device simultaneously, a single UL-OFDMA transmission can be usedto compute multiple channel responses associated with different motiondetection zones in the environment. Consequently, motion of objects inmultiple motion detection zones can be sensed simultaneously.

Beamforming dynamic information may be indicative of the behavior of, orinformation generated or used by, wireless communication devices inperforming beamforming operations over time. For example, beamformingdynamic information may include feedback or steering matrices generatedby wireless communication devices communicating according to an IEEE802.11 standard (e.g., the IEEE 802.11-2012 standard or the IEEE802.11ac-2013 standard). By analyzing changes in the beamforming dynamicinformation of wireless communication devices, motion in the space maybe inferred/detected. For example, in some implementations, feedback andsteering matrices generated by wireless communication devices in abeamforming wireless communication system may be analyzed over time todetect changes in the estate (which may be caused by motion of anobject). Beamforming may be performed between devices based on someknowledge of the channel state (e.g., through feedback propertiesgenerated by a receiver), which can be used to generate one or moresteering properties (e.g., a steering matrix) that are applied by atransmitter device to shape the transmitted beam/signal in a particulardirection or directions. Thus, changes to the steering or feedbackproperties used in the beamforming process indicate changes in thechannel state, which may be caused by moving objects in the spaceaccessed by the wireless communication system.

In some implementations, for example, a steering matrix may be generatedon a transmitter device (beamformer) based on a feedback matrixcommunicated to the transmitter device by a receiver device(beamformee), derived from channel sounding. Because the steering andfeedback matrices are related to propagation characteristics of thechannel, these matrices change as objects move within the channel.Changes in the channel characteristics are accordingly reflected inthese matrices, and by analyzing the matrices, motion can be detected,and different characteristics of the detected motion can be determined

Channel sounding may refer to the process performed to acquire ChannelState Information (CSI) from each of the different receiver devices in awireless communication system. In some instances, channel sounding isperformed by sending training symbols (e.g., a null data packet (NDP) asspecified in in the IEEE 802.11ac-2013 standard) and waiting for thereceiver devices to provide feedback that includes a measure of thechannel. In some instances, the feedback includes a feedback matrixcalculated by each of the receiver devices. This feedback may then beused to generate the steering matrix used to pre-code the datatransmission by creating a set of steered beams, which may optimizereception at one or more receiver devices. The channel sounding processmay be performed repeatedly by a wireless communication system. Thesteering matrix may therefore repeatedly update, such as, for example,to minimize the impact of the propagation channel change to the datatransmission quality. By observing changes in the steering matrix (orfeedback matrix) over time, motion by an object in the channel can bedetected. Further, in some cases, different categories of motion (e.g.,human motion vs. dog/cat motion) can be identified.

Changes in the beamforming or feedback matrices can be determined in anumber of ways. In some cases, for example, a variance for each entry inthe matrix is analyzed, or the linear independence of matrix columns(e.g., rank). This information can, for example, allow for determining anumber of independently fading paths present in the channel. In somecases, if the coefficients of this linear independence are changing, thechanges could be due to a moving object restricted to a certain zone. Ifthe number of linearly independent columns itself changes, the changescould be due to wide-spread changes across the channel, allowingdifferent kinds of multipath to be created and destroyed. In some cases,the time series of this inter-column correlation can be analyzed todetermine, for example, how slow or fast these changes are occurring.

In some instances, the beamforming is performed according to astandardized process. For example, the beamforming may be performedaccording to an IEEE 802.11 standard (e.g., 802.11n, 802.11ac, 802.11axstandards, etc.). The beamforming may be an optional or mandatoryfeature of the standard. Beamforming may be performed according toanother standard, or in another manner. In some cases, the 802.11standard applies adaptive beamforming using multi-antenna spatialdiversity to improve data transmission quality between network nodes.Moving objects change spatial characteristics of the environment bychanging multipath propagation of transmitted wireless signals. As aresult, such movement can influence a beamforming steering configurationperformed by a device according to the 802.11 standard. By observing howthe spatial configuration (e.g., beamforming) of the beamformer changesover time (e.g., via the steering matrix generated by the beamformerbased on a feedback matrix), physical motion within the area covered bywireless transmission may be detected.

FIG. 1 shows an example beamforming system 100, which includes abeamformer 110 and a beamformee 120. In general, beamforming is atechnique that focuses or steers a wireless signal (e.g., a radiofrequency (RF) signal) towards a specific receiving device, rather thanhaving the signal spread in all directions from a broadcast antenna. Inthe example of FIG. 1, the beamformer 110 may be configured to focus awireless signal towards the beamformee 120. The beamformer 110 mayinclude a transmitter 112 and a steering matrix calculator 116. Thebeamformee 120 may include a receiver 122 and a feedback matrixcalculator 126. In some implementations, the steering matrix calculator116 and the feedback matrix calculator 126 are implemented using generalor special purpose microprocessors, processors of any kind of digitalcomputer, or special purpose logic circuitry (e.g., a field programmablegate array or an application specific integrated circuit). Thebeamformer 110 and the beamformee 120 are communicatively coupled toeach other by a channel 130. The beamformer 110 sends a wireless signal102 using the transmitter 112 to the beamformee 120. Transmission of thewireless signal 102 is mediated through the channel 130. In someinstances, the signal 102 includes a null data packet (NDP), which mayfunction as a channel sounding packet. The beamformee 120 receives thesignal 102 using the receiver 122. In some cases, the transmitter 112and the receiver 122 each include multiple antennas and form amultiple-input/multiple-output (MIMO) system.

In some implementations, the beamformee 120 determines channel stateinformation (CSI) 124 based on the wireless signal(s) received at thereceiver 122. The beamformee 120 then computes, using the feedbackmatrix calculator 126, a feedback matrix 104 based on the CSI 124. Insome cases, the feedback matrix calculator 126 generates a feedbackmatrix 104 that is indicative of conditions of the channel 130.Therefore, changes within the feedback matrix 104 over time may beindicative of changes in conditions of the channel 130, which in turnmay be correlated to changes occurring in a spatial region spanned bythe channel 130 (e.g., a zone between the beamformer 110 and beamformee120). As a consequence, changes within the feedback matrix 104 over timemay be used to wirelessly sense changes occurring in the spatial regionspanned by the channel 130. As an example, changes within the feedbackmatrix 104 over time may be used for motion detection (e.g., presence,location, or intensity of motion), presence detection, gesturedetection, and other applications.

The feedback matrix 104 is sent by the beamformee 120 to the beamformer110. In some cases, the feedback matrix 104 is sent to the beamformer110 in a compressed format (e.g., as a compressed version of thefeedback matrix 104 computed by the feedback matrix calculator 126). Insome implementations, the feedback matrix calculator 126 generates aV-matrix or a compressed V-matrix (CV-matrix). The beamformer 110 thengenerates, using the steering matrix calculator 116, a steering matrix114 based on the feedback matrix 104. The steering matrix 114 is thenused by the transmitter 112 to focus or steer the next wireless signaltransmission to the beamformee 120.

In some implementations, the beamforming process performed by the system100 is based on a standard, such as, for example, an IEEE 802.11standard. In some cases, the beamforming system 100 can be modeled byEquation (1):

y _(k) =H _(k) Q _(k) x _(k) +n  (1)

where x_(k) represents a vector [x₁, x₂, . . . , x_(n)] transmitted insubcarrier frequency k by the transmitter 112, y_(k) represents a vector[y₁, y₂, . . . , y_(n)] received by the receiver 122, H_(k)represents achannel response matrix for sub carrier frequency k of dimensionsN_(RX)× N_(TX) (where N_(RX) is the number of antennas at the receiverand Nix is the number of antennas at the transmitter), Q_(k) is asteering matrix applied to the transmitted signal x_(k) and havingdimension N_(TX)×N_(STS) (where N_(STS) is the number of elements inx_(k)), and n represents white (spatially and temporally) Gaussiannoise.

In some implementations, explicit beamforming may be used. For example,explicit beamforming requires explicit feedback from the beamformee 120of the current channel state. In such implementations, the beamformee120 computes the channel matrices H_(k) based on the Long Training Field(LTF) included in a null data packet transmitted by the beamformer 110to the beamformee 120. The channel matrices H_(k) may then be encodedinto a matrix V_(k). In some cases, the matrix V_(k) is sent by thebeamformee 120 to the beamformer 110 in a Beamforming Report Field usingan Action No Ack Management Frame. The beamformee 120 may also perform asimilar beamforming process to determine a steering matrix for sendingbeamformed signals to the beamformer 110.

FIG. 2A is a diagram showing an example wireless communication networksystem 200. In some instances, the wireless communication network system200 is configured to operate as a Wireless Local Area Network (WLAN), aPersonal Area Network (PAN), a metropolitan area network (MAN), oranother type of wireless network. Examples of WLANs include networksconfigured to operate according to one or more of the 802.11 family ofstandards developed by IEEE (e.g., Wi-Fi networks), and others. Examplesof PANs include networks that operate according to short-rangecommunication standards (e.g., BLUETOOTH®, Near Field Communication(NFC), ZigBee), millimeter wave communications, and others.

The wireless communication network system 200 may include one or morewireless devices 220A, 220B, 220C, 220D and a wireless access point (AP)230. The wireless devices 220A, 220B, 220C, 220D can operate in thewireless communication network system 200, for example, according to awireless network standard or another type of wireless communicationprotocol. The wireless devices 220A, 220B, 220C, 220D may include, ormay be, a mobile device (e.g., a smartphone, a smart watch, a tablet, alaptop computer, etc.), a wireless-enabled device (e.g., a smartthermostat, a Wi-Fi enabled camera, a smart TV), or another type ofdevice that communicates in the wireless communication network system200. In some examples, one or more of the wireless devices 220A, 220B,220C, 220D (e.g., the wireless device 220D shown in FIG. 2A) may also beconfigured to communicate in a cellular network, for example, accordingto a cellular network standard. Examples of cellular networks includenetworks configured according to 2G standards such as Global System forMobile (GSM) and Enhanced Data rates for GSM Evolution (EDGE) or EGPRS;3G standards such as Code Division Multiple Access (CDMA), Wideband CodeDivision Multiple Access (WCDMA), Universal Mobile TelecommunicationsSystem (UMTS), and Time Division Synchronous Code Division MultipleAccess (TD-SCDMA); 4G standards such as Long-Term Evolution (LTE) andLTE-Advanced (LTE-A); 5G standards, and others.

In the example shown in FIG. 2A, the wireless devices 220A, 220B, 220C,220D are wirelessly connected to and in communication with the AP 230.In some implementations, the wireless devices 220A, 220B, 220C, 220D andthe AP 230 communicate to one another via RF signals, for example,according to the IEEE 802.11 family of standards or another standard. Insome implementations, the AP 230 may be an access point that allowswireless devices 220A, 220B, 220C, 220D to connect to a wired network ormay be a node of a wireless mesh network, such as, for example, acommercially available mesh network system (e.g., GOOGLE Wi-Fi, EEROmesh, etc.). In examples where the AP 230 is a node of a wireless meshnetwork, the wireless devices 220A, 220B, 220C, 220D may be leaf devices(e.g., mobile devices, smart devices, laptop computers, etc.) thataccess the mesh network through AP 230.

When the wireless devices 220A, 220B, 220C, 220D seek to connect to orcommunicate with the AP 230, the wireless devices 220A, 220B, 220C, 220Dmay go through an authentication and association phase with the AP 230.Among other things, the association phase assigns address information(e.g., an association ID or another type of unique identifier) to eachof the wireless devices 220A, 220B, 220C, 220D. For example, within theIEEE 802.11 family of standards for Wi-Fi, each of the wireless devices220A, 220B, 220C, 220D may identify itself using a unique 48-bit address(e.g., the MAC address), although the wireless devices 220A, 220B, 220C,220D may be identified using other types of identifiers embedded withinone or more fields of a message. The address information (e.g., MACaddress or another type of unique identifier) can be either hardcodedand fixed, or randomly generated according to the network address rulesat the start of the association process. Once the wireless devices 220A,220B, 220C, 220D have associated to the AP 230, their respective addressinformation may remain fixed. Subsequently, a transmission by the AP 230or the wireless devices 220A, 220B, 220C, 220D includes, at a minimum,the address information (e.g., MAC address) of the transmitting wirelessdevice and the address information (e.g., MAC address) of the receivingdevice (e.g., the AP 230). The address information (e.g., the MACaddresses of the transmitting and receiving devices) is not part of anencrypted or scrambled payload. Consequently, the identities of thetransmitting and receiving devices (e.g., as indicated by their addressinformation) may be accessible to a device that is within listeningrange of the communication and eavesdropping on the communicationbetween the transmitting and receiving devices. The identity of thetransmitting and receiving devices may, as an example, be used by theeavesdropping device to determine a link identifier that establishes theidentity of a respective link within the wireless communication networksystem 200.

A listening device 250-1 resides outside the wireless communicationnetwork system 200. For example, the listening device 250-1 is notconnected to, associated with, or communicating via the AP 230 or any ofthe wireless devices 220A, 220B, 220C, 220D. In some instances, thewireless communication network system 200 is unaware of the presence ofthe listening device 250-1. For example, the listening device 250-1 maynot go through the above-described authentication or association phaseand, as a result, none of the AP 230 or the wireless devices 220A, 220B,220C, 220D is aware of the existence or presence of the listening device250-1.

Although the listening device 250-1 is not connected to, associatedwith, or communicating via the wireless communication network system200, the listening device 250-1 may be within a listening range of thetransmissions occurring within the wireless communication network system200. As a result, the listening device 250-1 may eavesdrop onover-the-air (OTA) signals (e.g., wireless signals) exchanged among thewireless devices 220A, 220B, 220C, 220D and the AP 230. Such OTA signalsmay contain beamforming reports, physical (PHY) frames, or a combinationthereof. Furthermore, each OTA signal transmitted in the wirelesscommunication network system 200 may be associated with a respectivelink since, as described above, each OTA signal may include or containaddress information (e.g., MAC addresses or another type of uniqueidentifier) of the transmitting and receiving devices. The listeningrange within which eavesdropping may occur may depend, at least in part,on a frequency band used for the OTA signals or the physical propertiesof the environment (e.g., the channel 130 in FIG. 1) through with theOTA signals are exchanged. As an example, the listening range for 2.4GHz Wi-Fi signals may be from about 50 feet to about 100 feet. As afurther example, the listening range for sub-GHz (e.g., 900 MHz) signalsmay be greater than about 1 kilometer.

As discussed above, the OTA signals may contain beamforming reports.Such beamforming reports may be auxiliary information exchangedover-the-air between communicating devices and may be used to optimizeperformance (e.g., improve data transmission rate or signal-to-noiseratio (SNR)) through the process of beamforming. Information within thebeamforming reports may directly or indirectly (e.g., through atransformation) represent a channel response or channel state. Forexample, in some cases, MIMO systems require measuring andcharacterizing the propagation between two communicating wirelessdevices. Such measurement and characterization of the propagation may beused to perform beamforming or beamsteering in order to optimizeperformance. In the example of FIG. 2A, the AP 230 or one or more of thewireless devices 220A, 220B, 220C, 220D may support MIMO beamforming.Therefore, the AP 230 or one or more of the wireless devices 220A, 220B,220C, 220D may perform a periodic channel characterization of acommunication link between two communicating devices. In someimplementations of the periodic channel characterization, a two-wayexchange is performed between a source device (e.g., beamformer 110described in FIG. 1) and a destination device (e.g., beamformee 120described in FIG. 1). As an example, the AP 230 (e.g., the source deviceor beamformer 110) may send a sounding request to the wireless device220B (e.g., the destination device or beamformee 120). The wirelessdevice 220B receives and analyzes the signal, and sends a measurementresult (e.g., a channel response) to the AP 230. The measurement resultmay be sent to the AP 230 in the form of a beamforming report 260 (e.g.,feedback matrix 104 in FIG. 1). This process occurs periodically tomaintain good beamforming performance between the wireless device 220Band the AP 230. In this example, both parts of the beamformingexchange—the sounding request and the measurement result—occurover-the-air. As a result, the listening device 250-1, which is withinlistening range of the wireless communication network system 200, mayeavesdrop on the beamforming report 260 sent by the wireless device 220Bto the AP 230.

As discussed above, each OTA communication by the wireless devices 220A,220B, 220C, 220D and the AP 230 includes address information (e.g., theMAC addresses) of the transmitting device and the receiving device.Additionally, the address information is not part of an encrypted orscrambled payload. Therefore, when OTA signals are transmitted withinthe wireless communication network system 200, both the channel responsepayload (e.g., included in the beamforming report 260) and the addressinformation of the devices involved in the exchange are accessible tothe listening device 250-1. Therefore, each beamforming report 260 isassociated with a respective link within the wireless communicationnetwork system 200 (e.g., a physical path between the wireless device220B and the AP 230 in the example of FIG. 2A). Consequently, eachbeamforming report 260 is indicative of the channel response or channelstate of a given link within the wireless communication network system200. Through repeated observations of the beamforming reports 260exchanged between the wireless device 220B and the AP 230, wirelesssensing of the link between the wireless device 220B and the AP 230 maybe performed. As an example, changes within the beamforming reports 260over time may be used to detect motion (e.g., presence, location, orintensity of motion), the presence of an object, or a gesture occurringin the spatial region between the wireless device 220B and the AP 230.In the example described above, the sounding request and measurementresult are exchanged between the wireless device 220B and the AP 230;however, in other examples, the sounding request and measurement resultare exchanged between any pair of devices selected from the wirelessdevices 220A, 220B, 220C, 220D and the AP 230 (e.g., the AP 230 and thewireless device 220C shown in FIG. 2A).

As discussed above, the OTA signals may contain a physical (PHY) frame,e.g., transmitted by the AP 230 or one or more of the wireless devices220A, 220B, 220C, 220D. As an illustration, in the example shown in FIG.2A, a PHY frame is transmitted over-the-air by the wireless devices 220Aand 220D; however, in other examples, the PHY frame may be transmittedby any of the wireless devices 220A, 220B, 220C, 220D and AP 230. In anexample (e.g., in an 802.11 transmission), the PHY frame may include apreamble containing training fields 270. The preamble or the trainingfield 270 of the PHY frame may be used to compute the channel response(e.g., in a decoded 802.11 transmission), although other fields orportions of the PHY frame may, additionally or alternatively, be used tocompute the channel response. The listening device 250-1, which iswithin listening range of the wireless communication network system 200,may eavesdrop on the PHY frame. The PHY frame may also include theaddress information (e.g., MAC address) of the transmitting device. Incontrast to the link associated with the beamforming report 260, thelink associated with the channel response computed from the PHY framemay correspond to a physical path between the device transmitting thePHY frame and the listening device 250-1. Consequently, while the linkassociated with the beamforming report 260 may represent an environmentcontained within the wireless communication network system 200 (e.g.,the physical path between the devices involved in the exchange, asindicated by their address information), the link associated with thechannel response computed from the PHY frame may represent anenvironment that at least partially extends outside the wirelesscommunication network system 200 (e.g., the physical path between thedevice transmitting the PHY frame and the listening device 250-1).Nonetheless, through repeated observations of the PHY frames, wirelesssensing of the link between the transmitting device and the listeningdevice 250-1 may be performed. As an example, changes within the channelresponse over time may be used to detect motion (e.g., presence,location, or intensity of motion), the presence of an object, or agesture occurring in the spatial region between the transmitting deviceand the listening device 250-1.

FIG. 9 shows an example of a PHY frame 900 including a preamblecontaining training fields. The example PHY frame 900 may be transmittedin an 802.11 communication. In the example of FIG. 9, OTA transmissionsof the PHY frame 900 (e.g., on a Wi-Fi network) may begin with a legacypreamble 902 (e.g., lasting 20 microseconds), and may contain MIMOmodulated components 904. The legacy preamble 902 may contain aLegacy-Long-Training-Field (L-LTF) 906. The MIMO modulated data maycontain one or more VHT-Long-Training-Fields (VHT-LTF1 to VHT-LTFn) 908.The legacy training field 906 or VHT training fields 908 may be used(e.g., by commercially available Wi-Fi transceivers) to compute thechannel response.

The PHY frame 900 also includes a PHY data payload 910. Encoded withinthe PHY data payload 910 is a Media Access Control (MAC) layer frame912. In the example of FIG. 9, the MAC layer frame 912 illustrates adigitally encoded transmission payload. Each MAC layer frame 912 mayinclude a frame header 914 and a frame body 916. The frame header 914may indicate information about data encapsulated in the frame body 916.In some examples, the frame header 914 includes the transmitter MACaddress 918 and the receiver MAC address 920. In the example of FIG. 9,the frame body 916 is of a Management type and Action-No-Ack subtype(e.g., as illustrated in fields 922 and 924 of the frame header 914). Insome examples, the Management type and Action-No-Ack subtype frame isused to carry beamform report payloads.

In some cases, transmission of PHY frames (e.g., by the AP 230 or any ofthe wireless devices 220A, 220B, 220C, 220D) occurs more frequently thanthe exchange of beamforming reports 260. Therefore, wireless sensingbased on the PHY frames may have a higher temporal resolution comparedto wireless sensing based on the beamforming reports 260. In someexamples, wireless sensing based on the PHY frames (e.g., containing thepreamble or training field 270) may be augmented or combined withwireless sensing based on the beamforming reports 260 (e.g., asdescribed in greater detail below in FIGS. 4 to 7).

FIG. 3A is a diagram showing an example of an environment 300 includingthe wireless communication network system 200. The OTA signalscommunicated on the wireless communication network system 200 aretransmitted through a physical space of the environment 300. Hence, suchOTA signals can be used for wireless sensing (e.g., motion detection) inthe physical space of the environment 300. Although depicted as being aclosed area in FIG. 3A, the environment 300 can be an indoor space or anoutdoor space, which may include, for example, one or more fully orpartially enclosed areas, an open area without enclosure, etc. The spacecan be or can include an interior of a room, multiple rooms, a building,or the like. As an example, the environment 300 may be a building, e.g.,an office building or home, a room in the building, a combination of oneor more rooms, or other space within the building, such as a hall orstairwell. The listening device 250-1 may reside remove from (e.g.,outside) the environment 300.

As discussed above in FIG. 2A, none of the AP 230 or the wirelessdevices 220A, 220B, 220C, 220D is aware of the existence or presence ofthe listening device 250-1. However, the wireless devices 220A, 220B,220C, 220D and the AP 230 are within listening range of the listeningdevice 250-1. The wireless devices 220A, 220B, 220C, 220D and the AP 230may produce and exchange OTA signals containing beamforming reports 260as they communicate among each other within the environment 300. In someimplementations, each time the AP 230 or one of the wireless devices220A, 220B, 220C, 220D transmits information, a PHY frame (e.g.,containing the preamble or training field 270) is also transmitted. Insome instances, an object 340 may be present within the environment 300.Generally, the object 340 can be any type of static or moveable objectand can be living or inanimate. For example, the object 340 can be ahuman (e.g., as shown in the example of FIG. 3A), an animal, aninorganic object, or another device, apparatus, or assembly, an objectthat defines all or part of the boundary of a space (e.g., a wall, door,window, etc.), or another type of object.

The object 340 may be moving within the environment 300 (e.g., along amovement path 345 within the environment 300). One or more of the OTAsignals transmitted within the environment 300 (e.g., containing thebeamforming reports 260 or PHY frames) may be affected by the movingobject 340. Unbeknownst to the wireless devices 220A, 220B, 220C, 220Dand the AP 230, the listening device 250-1 may eavesdrop on, collect,and organize the OTA signals containing the beamforming reports 260 andthe PHY frames.

FIG. 4 shows an example of OTA signals 400-1 to 400-4 collected andorganized by the listening device 250-1. In example of FIG. 4, a firstsubset of the wireless signals may include the OTA signal 400-1 and theOTA signal 400-3. The OTA signal 400-1 contains a beamforming report410A and address information 430A associated with the beamforming report410A, while the OTA signal 400-3 contains a beamforming report 410B andaddress information 430B associated with the beamforming report 410B.The address information 430A, 430B may include, as an example, sourceand destination information (e.g., MAC addresses or another type ofunique identifier). Therefore, the first subset of wireless signals mayinclude wireless signals containing beamforming reports 410A, 410B,where each of the beamforming reports 410A, 410B is associated with acorresponding wireless link (e.g., a transmitter-receiver pair orsource-destination pair as indicated by the address information 430A,430B). As described above, information within the beamforming reports410A, 410B may directly or indirectly (e.g., through a transformation)represent a channel response or channel state on their correspondingwireless link.

In some instances, the beamforming reports 410A, 410B may include, ormay be, a type of standardized beamforming report, an example being theCSI or H-matrix, V-matrix, or CV-matrix beamforming reports defined inthe 802.11 standards, although the beamforming reports 410A, 410B may beother types of dynamic beamforming information. In implementations wherethe beamforming reports 410A, 410B include, or are, standardizedbeamforming reports defined in the 802.11 standards, the CSI-matrix,V-matrix, or CV-matrix beamforming reports may be derived from theH-matrix defined in the 802.11 standards, where the H-matrix includesthe magnitude and phase response for each subcarrier frequency. In someexamples, the CSI-matrix, V-matrix, or CV-matrix beamforming reports mayundergo further transformations to better match the needs of thebeamforming application.

In the example of FIG. 4, a second subset of the wireless signals mayinclude the OTA signal 400-2 and the OTA signal 400-4. The OTA signal400-2 contains a PHY frame (e.g., including preamble or training field420A) and address information 440A associated with the preamble ortraining field 420A, while the OTA signal 400-4 contains a PHY frame(e.g., including preamble or training field 420B) and addressinformation 440B associated with the preamble or training field 420B.The address information 440A, 440B may include, as an example, sourceand destination information (e.g., one or more MAC addresses or anothertype of unique identifier). Therefore, the second subset of wirelesssignals may include wireless signals containing preamble or trainingfields 420A, 420B, where each of the preamble or training fields 420A,420B is associated with a corresponding wireless link (e.g., atransmitter-receiver pair or source-destination pair as indicated by theaddress information 440A, 440B). After the OTA signals 400-1 to 400-4are collected and organized by the listening device 250-1, the first andsecond subsets of the wireless signals undergo a processing step 450,which may be performed by one or more processors. While the example ofFIG. 4 illustrates the first subset of wireless signals as having twoOTA signals 400-1 and 400-3 and the second subset of wireless signals ashaving two OTA signals 400-2 and 400-4, in operation, more than two OTAsignals may be included in each of the first and second subsets ofwireless signals.

FIG. 5 shows an example of the operations 500 that may be performed bythe one or more processors that execute the processing step 450 shown inFIG. 4. At 502, a first set of motion data is generated (e.g., using afirst type of motion detection process) based on the first subset ofwireless signals (e.g., the OTA signals 400-1 and 400-3). The first setof motion data may include a first set of motion scores and a first setof link identifiers. In some examples, the first set of motion scoresmay be generated based on the beamforming reports 410A, 410B since thebeamforming reports 410A, 410B may directly or indirectly (e.g., througha transformation) represent a channel response or channel state on theircorresponding wireless link. The first set of link identifiers may begenerated based on the address information 430A, 430B.

At 504, a second set of motion data is generated (e.g., using a secondtype of motion detection process) based on the second subset of wirelesssignals (e.g., the OTA signals 400-2 and 400-4). The second set ofmotion data may include a second set of motion scores, which may bebased on channel responses computed from PHY frames (e.g., including thepreamble or training fields 420A, 420B) using, as an example, PHYchannel estimation. In some instances, the PHY channel estimation is notdefined by a standard and is, instead, left to the manufacturer of thereceiver to implement an algorithm to compute the channel response. Thesecond set of motion data may further include a second set of linkidentifiers, which may be generated based on the address information440A, 440B. In some examples, the second set of link identifiers mayinclude some or all of links included in the first set of linkidentifiers.

Example types of motion detection processes that can be used to generatethe first and second sets of motion scores include the techniquesdescribed in U.S. Pat. No. 9,523,760 entitled “Detecting Motion Based onRepeated Wireless Transmissions,” U.S. Pat. No. 9,584,974 entitled“Detecting Motion Based on Reference Signal Transmissions,” U.S. Pat.No. 10,051,414 entitled “Detecting Motion Based On Decompositions OfChannel Response Variations,” U.S. Pat. No. 10,048,350 entitled “MotionDetection Based on Groupings of Statistical Parameters of WirelessSignals,” U.S. Pat. No. 10,108,903 entitled “Motion Detection Based onMachine Learning of Wireless Signal Properties,” U.S. Pat. No.10,109,167 entitled “Motion Localization in a Wireless Mesh NetworkBased on Motion Indicator Values,” U.S. Pat. No. 10,109,168 entitled“Motion Localization Based on Channel Response Characteristics,” U.S.Pat. No. 10,459,076 entitled “Motion Detection Based on BeamformingDynamic Information,” and other techniques. As an example, a first typeof motion detection process that operates on the beamforming reports410A, 410B (e.g., as described in U.S. Pat. No. 10,459,076 entitled“Motion Detection Based on Beamforming Dynamic Information”) may be usedto generate the first set of motion scores, while a second type ofmotion detection process that operates on the channel responses computedfrom the preamble or training fields 420A, 420B (e.g., as described inU.S. Pat. No. 9,584,974 entitled “Detecting Motion Based on ReferenceSignal Transmissions”) may be used to generate the second set of motionscores.

Each of the first and second sets of motion scores may include, or maybe, a scalar quantity indicative of a level of signal perturbation inthe environment (e.g., the environment 300) accessed by the first andsecond subsets of wireless signals, respectively. Additionally oralternatively, the first and second sets of motion scores may include,or may be, an indication of whether there is motion, whether there is anobject present, or an indication or classification of a gestureperformed in the environment accessed by the first and second subsets ofwireless signals, respectively.

At 506, the one or more processors may generate a combined motion dataset including the first and second sets of motion data. In someimplementations, the first set of motion data and the second set ofmotion data may be input into a logical OR operator to generate thecombined motion data set. In some implementations, a weighted sum of thefirst set of motion data and the second set of motion data may be usedto generate the combined motion data set.

At 508, motion within the environment accessed by the first and secondsubsets of wireless signals is analyzed based on the combined motiondata set. In some implementations, analyzing motion within theenvironment based on the combined motion data set may includedetermining whether motion occurred within the environment. Additionallyor alternatively, analyzing motion within the environment based on thecombined motion data set may include determining the location orintensity of motion performed in the environment.

An advantage of generating a combined motion data set including thefirst and second sets of motion data (e.g., at 506) is that subsequentmotion analysis (e.g., at 508) may be based on the combined motion dataset, thereby giving a broader or more accurate view of motion occurringwithin the environment accessed by the first and second subsets ofwireless signals compared to cases where only the first set of motiondata or the second set of motion data is used to analyze motion. In someexamples (such as in the examples shown in FIGS. 2A and 3A), thelistening device 250-1 may include the one or more processors.Therefore, in some implementations of the examples shown in FIGS. 2A and3A, the listening device 250-1 executes the operations 502, 504, 506,and 508 shown in FIG. 5.

In some examples (such as in the examples shown in FIGS. 2B and 3B), thelistening device 250-1 is communicatively coupled (e.g., by a wired orwireless communications link) to a processing device 280 that is alsoresiding outside the environment 300. The processing device 280 is notconnected to, associated with, or communicating via the AP 230 or any ofthe wireless devices 220A, 220B, 220C, 220D. The processing device 280may be a cloud-based device or a non-cloud-based device. In the examplesshown in FIGS. 2B and 3B, the listening device 250-1 may include a firstprocessor 282, while the processing device 280 may include a secondprocessor 284. In some implementations of the examples shown in FIGS. 2Band 3B, the first processor 282 (and consequently the listening device250-1) may be configured to perform operations 502, 504, and 506, whilethe second processor 284 (and consequently the processing device 280)may be configured to perform operation 508. In other implementations ofthe examples shown in FIGS. 2B and 3B, the first processor 282 (andconsequently the listening device 250-1) may be configured to performoperations 502 and 504, while the second processor 284 (and consequentlythe processing device 280) may be configured to perform operations 506and 508.

In some examples (such as in the examples shown in FIGS. 2C and 3C), thelistening device 250-1 is communicatively coupled (e.g., by a wired orwireless communications link) to a processing device 286 that is alsoresiding outside the environment 300. The processing device 286, whichmay be a cloud-based device or a non-cloud-based device, is notconnected to, associated with, or communicating via the AP 230 or any ofthe wireless devices 220A, 220B, 220C, 220D. In some implementations ofthe examples shown FIGS. 2C and 3C, the listening device 250-1 may actas a relay to communicate the beamforming reports (e.g., the beamformingreports 260 in FIGS. 2C and 3C or the beamforming reports 410A, 410B inFIG. 4) and the PHY frames (e.g., containing the preamble or trainingfields 270 in FIGS. 2C and 3C or the preamble or training fields 420A,420B in FIG. 4) to the processing device 286. In such implementations,the processing device 286 may be configured to execute the operations502, 504, 506, and 508 shown in FIG. 5.

In some examples (such as in the examples shown in FIGS. 2D and 3D), thelistening device 250-1 is a first listening device. A second listeningdevice 250-2 resides outside the environment 300 and at a location thatis different from the location of the listening device 250-1. Like thelistening device 250-1, the second listening device 250-2 is notconnected to, associated with, or communicating via the AP 230 or any ofthe wireless devices 220A, 220B, 220C, 220D. The second listening device250-2 may also be within a listening range of the wireless communicationnetwork system 200 and may eavesdrop on, collect, and organize the OTAsignals communicated by devices in the wireless communication networksystem 200. The OTA signals received by the second listening device250-2 may contain beamforming reports (e.g., the beamforming reports 260in FIGS. 2D and 3D or the beamforming reports 410A, 410B in FIG. 4) andPHY frames (e.g., containing the preamble or training fields 270 inFIGS. 2D and 3D or the preamble or training fields 420A, 420B in FIG.4). The second listening device 250-2 may be configured to generate itsown set of motion data 288 including a set of motion scores and a set oflink identifiers based on the OTA signals received by the secondlistening device 250-2. An advantage of having a plurality of listeningdevices 250-1, 250-2 is that analysis of motion within the environment300 is based on a combined motion data set that includes theabove-described first and second sets of motion data as well as the setof motion data 288 generated by the second listening device 250-2, whichin turn leads to a more accurate analysis of motion occurring within theenvironment 300. The second listening device 250-2 may be configured totransmit its own set of motion data 288 to the listening device 250-1.In some implementations of the examples shown in FIGS. 2D and 3D, thelistening device 250-1 generates the combined motion data set (thatincludes the first and second sets of motion data generated by thelistening device 250-1 and the set of motion data 288 generated by thesecond listening device 250-2) and analyzes motion within theenvironment 300 based on the combined motion data set.

In some examples (such as in the examples shown in FIGS. 2E and 3E), thelistening device 250-1 is communicatively coupled (e.g., by a wired orwireless communications link) to a processing device 290 that is alsoresiding outside the environment 300. The processing device 290, whichmay be a cloud-based device or a non-cloud-based device, is notconnected to, associated with, or communicating via the AP 230 or any ofthe wireless devices 220A, 220B, 220C, 220D. In some implementations ofthe examples shown in FIGS. 2E and 3E, the listening device 250-1generates the combined motion data set (that includes the first andsecond sets of motion data generated by the listening device 250-1 andthe set of motion data 288 generated by the second listening device250-2). The listening device 250-1 subsequently transmits the combinedmotion data set to the processing device 290, which may be configured toanalyze motion within the environment 300 based on the combined motiondata set.

While the examples shown in FIGS. 2A to 2E and 3A to 3E illustrate theAP 230 as being included in the wireless communication network system200, some implementations of the wireless communication network system200 may be devoid of the AP 230. In such instances, the wireless devices220A, 220B, 220C, 220D may communicate within the wireless communicationnetwork system 200 using an ad-hoc peer-to-peer wireless network thatexchanges beamforming reports 260 and PHY frames (e.g., includingpreambles containing training fields 270). Consequently, theabove-described operations apply analogously and equally to instanceswhere the wireless network that connects the wireless devices 220A,220B, 220C, 220D includes or is an ad-hoc peer-to-peer wireless network.

FIG. 6 is a diagram showing an example 600 of processing of wirelessinformation to extract motion data at the listening device 250-1. Theexample 600 of FIG. 6 may also be applicable to implementations wherewireless information is processed at the above-described processingdevice 280, 286, or 290, as the case may be, to extract motion data. Inexample 600, the listening device 250-1 may observe one of several typesof transmissions. In one instance, any one of beamforming reports 610A,610B, 610C transmitted between any two devices in the environment 300(e.g., any pair selected from the AP 230 and the wireless devices 220A,220B, 220C, 220D) may be observed by the listening device 250-1.Beamforming reports 610A, 610B, 610C may have different formats, e.g.,CSI or H-matrix 610A, V-matrix 610B, or CV-matrix 610C, as describedabove. A wireless link may be identified by a transmitting MAC Addressand a receiving MAC Address pair associated with a particular wirelesssignal. As described above, in some instances, when a beamforming reportis transmitted, the channel response payload as well as the MAC addressof the two parties involved in the exchange may be accessible to thelistening device 250-1. Thus, each wireless link may be identified basedon the MAC addresses and, each wireless link can represent the physicalpath between the two identified devices.

In some instances, the listening device 250-1 may identify the wirelesslink between two distinct devices by analyzing the source anddestination information in the wireless signal. In some instances, thelistening device 250-1 may identify a wireless link based on the MACaddress of the transmitting device (e.g., TX MAC Address 6101A) and theMAC address of the receiving device (e.g., RX MAC address 6102A) in thewireless signal including the CSI Beamform Report 610A. In someimplementations, each beamforming report is fed to its correspondingmotion algorithm. For example, a CSI-Beamform Report 610A is processedby a CSI-Motion Algorithm 620A, a V-Beamform Report 610B is processed bya V-Motion Algorithm 620B, and a CV-Beamform Report 610C is processed bya CV-Motion Algorithm 620C. In some cases, each of the motion algorithmsoutput data related to motion affecting the wireless signals transmittedbetween two devices. Because the listening device 250-1 can associatebeamforming reports 610A, 610B, 610C with wireless links associated withthe wireless communication network system 200 contained in theenvironment 300, the motion data for the wireless links is constrainedto that particular environment 300.

In other instances, the listening device 250-1 may observe transmissionsof PHY frames (e.g., including preambles or training fields) by one ormore wireless devices. Similar to the beamforming report transmissions,the listening device 250-1 may obtain the MAC address of the transmitterof the PHY frame, and then identify the wireless link represented by thephysical path between the transmitter device and the listening device250-1 (e.g., device to sensor). The listening device 250-1 performschannel estimation 610D using the PHY frame (e.g., using the preamblesor training fields of the PHY frame). In this case, the channelestimation is associated with the channel quality of the link betweenthe transmitting device and the listening device 250-1 and not the linkbetween the transmitting device and the receiving device for which thewireless signal was addressed. Typically, the listening device 250-1 isinterested in wireless signals transmitted in and through theenvironment 300. Therefore, in some instances, the listening device250-1 analyzes the signal to determine if the wireless signal isassociated with a wireless link between two wireless devices in theenvironment 300. For example, using the TX MAC Address 6101D and RX MACAddress 6102D of the wireless signal, the listening device 250-1 maydetermine whether the wireless signal including the PHY frame wastransmitted on a wireless link corresponding to a wireless link in theenvironment 300. As another example, based on received signalstrength/power and wireless link identification (e.g.,transmitter+receiver MAC address), the physical distance to thelistening device 250-1 can be estimated. This may enhance the ability toexclude devices that reside outside a desired environment 300 but thatare still within listening range of the listening device 250-1. Thereceived signal strength/power can be, for example, aSignal-To-Noise-Ratio (SNR) (e.g., represented in dB as the ratiobetween signal-power to noise-power) computed by the listening device250-1, a Receive-Signal-Strength-Indicator (RSSI) (a measure of signalpower received) computed by the listening device 250-1, or another typeof value.

In cases in which the wireless signal is associated with a wireless linkin the environment 300, the listening device performs channel estimationprocessing on the PHY frame training field. In cases in which thewireless signal is not associated with a link in the remote environment300, the listening device 350 may ignore the wireless signal and performno further processing. In some implementations, each PHY channelestimation is fed to its corresponding motion algorithm, e.g., PHYChannel Estimation Motion Algorithm 620D, to extract motion information.

In some implementations, one or more received and observed data 610A,610B, 610C, 610D, are obtained by the listening device 250-1 over a timeperiod. In some cases, multiple instances of the same type ofbeamforming report or multiple PHY signals may be observed or received.In other cases, no instances of one or more types of beamforming reportsmay be received. However, in most cases, it is expected that at leastone PHY signal associated with a link in the environment 300 is receivedby the listening device 250-1 as these signals are typically transmittedmore frequently than beamforming reports. In some implementations, thelistening device accumulates beamform reports 610A, 610B, 610C that areobserved, and PHY frames (e.g., including preambles or training fields)received over a period of time.

In some implementations, the output of a motion algorithm 620A, 620B,620C, 620D is fed to a corresponding process that converts motion dataextracted by a respective motion algorithm to a relative motionamplitude or score 630A, 630B, 630C, 630D. While the motion algorithms620A, 620B, 620C, 620D may have some similarities between them, they aremanaged separately. In some instances, the motion amplitudes or scores630A, 630B, 630C, 630D for each type of motion data provide the data ina common format for all types of received or observed data in theenvironment 300. In some instances, motion amplitudes or scores 630A,630B, 630C, 630D are determined for each wireless link, e.g., aparticular TX MAC Address/RX MAC Address pair. The motionamplitude/scores for each wireless link are combined (e.g., summed 640)to derive a combined motion links value 650 associated with the wirelesslinks.

In some cases, the motion amplitude score may be or include a motionindicator value. In an example, if motion is detected based on thereceived or observed data 610A, 610B, 610C, 610D after being processedby its corresponding motion algorithm 620A, 620B, 620C, 620D, then amotion indicator value (MIV) may be computed by the listening device250-1. The MIV represents a degree of motion detected by the devicebased on the beamform reports 610A, 610B, 610C, or preamble or trainingfields 610D received by the listening device 250-1. For instance, higherMIVs can indicate a high level of channel perturbation (due to themotion detected), while lower MIVs can indicate lower levels of channelperturbation. Higher levels of channel perturbation may indicate motionin close proximity to the device. The MIVs may include aggregate MIVs(representing a degree of motion detected in the aggregate by thelistening device 250-1 based on PHY training fields), link MIVs(representing a degree of motion detected on particular communicationlinks between respective devices in the environment 300), or acombination thereof. In some implementations, MIVs are normalized, e.g.,to a value from zero (0) to one hundred (100).

FIG. 7 is a diagram showing a flowchart showing an example process 700for detecting motion in a remote environment by a listening device oranother type of sensor device. For example, the process 700 may beperformed by the listening device 250-1, the processing device 280, 286,or 290, or by another type of sensor device. In some cases, one or moreof the operations shown in FIG. 7 are implemented as processes thatinclude multiple operations, sub-processes or other types of routines.In some cases, operations can be combined, performed in another order,performed in parallel, iterated, or otherwise repeated or performedanother manner.

At 710, the sensor device eavesdrops or listens to Wi-Fi air traffic andidentifies and receives beamforming reports. At 720, the sensor deviceassociates each beamforming report with a respective wireless link usingthe receiver and transmitter MAC addresses (e.g., as discussed above inreference to FIG. 6). At 730, for each wireless link, a time field ofreceived beamforming reports is processed using a suitable motiondetection process (e.g., an algorithm corresponding to detecting motionbased on beamforming reports). The result of 730 is a first set ofmotion data.

At 740, the sensor device eavesdrops or listens to Wi-Fi air traffic andidentifies and receives normal data transmissions (e.g., including PHYframes). At 750, the sensor device uses preambles or training fields tocompute channel responses and identifies a transmitter using a MACaddress, thereby associating each channel response with a respectivetransmitter. At 760, for each transmitter, a time field of receivedchannel responses is processed using a suitable motion detection process(e.g., an algorithm corresponding to detecting motion based on normaldata transmissions including PHY frames). The result of 760 is a secondset of motion data. At 770, the motion detection results from all linksand sources are combined to analyze or monitor motion in a remoteenvironment (e.g., environment 300 that is remote from the listeningdevice 250-1 or the processing devices 280, 286, and 290).

FIG. 8 is a block diagram showing an example wireless sensor device 800.In some implementations, the wireless sensor device 800 may beconfigured as the listening device 250-1 described above. As shown inFIG. 8, the example wireless sensor device 800 includes an interface830, a processor 810, a memory 820, and a power unit 840. In someimplementations, the interface 830, processor 810, memory 820, and powerunit 840 of the sensor device 800 are housed together in a commonhousing or other assembly. In some implementations, one or more of thecomponents of a wireless communication device can be housed separately,for example, in a separate housing or other assembly.

The example interface 830 can communicate (receive, transmit, or both)wireless signals. For example, the interface 830 may be configured toreceive radio frequency (RF) signals formatted according to a wirelesscommunication standard (e.g., Wi-Fi or Bluetooth), e.g., wirelesssignals transmitted by wireless devices in a remote environment, orother wireless devices within listening range of the wireless sensordevice. In some cases, the interface 830 may be configured to transmitsignals, e.g., to transfer data to a server or other device, but ininstances where the wireless sensor device is passive or operates in apassive mode, it does not communicate with the remote environment (e.g.,as described in FIGS. 2A to 2E and 3A to 3E). In some cases, the exampleinterface 830 may be implemented as a modem. In some implementations,the example interface 830 includes a radio subsystem and a basebandsubsystem. In some cases, the baseband subsystem and radio subsystem canbe implemented on a common chip or chipset, or they may be implementedin a card or another type of assembled device. The baseband subsystemcan be coupled to the radio subsystem, for example, by leads, pins,wires, or other types of connections.

In some cases, a radio subsystem in the interface 830 can include one ormore antennas and radio frequency circuitry. The radio frequencycircuitry can include, for example, circuitry that filters, amplifies orotherwise conditions analog signals, circuitry that up-converts basebandsignals to RF signals, circuitry that down-converts RF signals tobaseband signals, etc. Such circuitry may include, for example, filters,amplifiers, mixers, a local oscillator, etc. The radio subsystem can beconfigured to receive radio frequency wireless signals on the wirelesscommunication channels. As an example, the radio subsystem may include aradio chip, an RF front end, and one or more antennas. A radio subsystemmay include additional or different components. In some implementations,the radio subsystem can be or include the radio electronics (e.g., RFfront end, radio chip, or analogous components) from a conventionalmodem, for example, from a Wi-Fi modem, pico base station modem, etc. Insome implementations, the antenna includes multiple antennas.

In some cases, a baseband subsystem in the interface 830 can include,for example, digital electronics configured to process digital basebanddata. As an example, the baseband subsystem may include a baseband chip.A baseband subsystem may include additional or different components. Insome cases, the baseband subsystem may include a digital signalprocessor (DSP) device or another type of processor device. In somecases, the baseband system includes digital processing logic to operatethe radio subsystem, to communicate wireless network traffic through theradio subsystem, to extract channel response information from PHY framepreamble training signals, or to perform other types of processes. Forinstance, the baseband subsystem may include one or more chips,chipsets, or other types of devices that are configured to encodesignals and deliver the encoded signals to the radio subsystem fortransmission, or to identify and analyze data encoded in signals fromthe radio subsystem (e.g., by decoding the signals according to awireless communication standard, by processing the signals according toa motion detection process, or otherwise).

In some instances, the radio subsystem in the example interface 830receives baseband signals from the baseband subsystem, up-converts thebaseband signals to radio frequency (RF) signals, and wirelesslytransmits the radio frequency signals (e.g., through an antenna). Insome instances, the radio subsystem in the example interface 830wirelessly receives radio frequency signals (e.g., through an antenna),down-converts the radio frequency signals to baseband signals, and sendsthe baseband signals to the baseband subsystem. The signals exchangedbetween the radio subsystem and the baseband subsystem may be digital oranalog signals. In some examples, the baseband subsystem includesconversion circuitry (e.g., a digital-to-analog converter, ananalog-to-digital converter) and exchanges analog signals with the radiosubsystem. In some examples, the radio subsystem includes conversioncircuitry (e.g., a digital-to-analog converter, an analog-to-digitalconverter) and exchanges digital signals with the baseband subsystem.

The example processor 810 can execute instructions, for example, togenerate output data based on data inputs. The instructions can includeprograms, codes, scripts, modules, or other types of data stored inmemory 820. Additionally or alternatively, the instructions can beencoded as pre-programmed or re-programmable logic circuits, logicgates, or other types of hardware or firmware components or modules. Theprocessor 810 may be or include a general-purpose microprocessor, as aspecialized co-processor or another type of data processing apparatus.In some cases, the processor 810 performs high level operation of thewireless sensor device 800. For example, the processor 810 may beconfigured to execute or interpret software, scripts, programs, modules,functions, executables, or other instructions stored in the memory 820.In some implementations, the processor 810 be included in the interface830. In some instances, processor 810 may be configured to executeinstructions that cause the wireless sensor device 800 to detect motionin a remote environment, e.g., by the process described in FIG. 7.

The example memory 820 may include computer-readable storage media, forexample, a volatile memory device, a non-volatile memory device, orboth. The memory 820 may include one or more read-only memory devices,random-access memory devices, buffer memory devices, or a combination ofthese and other types of memory devices. In some instances, one or morecomponents of the memory can be integrated or otherwise associated withanother component of the wireless communication device 800. The memory820 may store instructions that are executable by the processor 810. Forexample, the instructions may be stored in passive motion detection 822module in memory 820. The instructions may include instructions forobtaining first channel response information including signalstransmitted wirelessly on a communication network in a remoteenvironment, each signal including a beamforming report, and associatingeach beamforming report with a respective wireless link in the remoteenvironment, each wireless link corresponding to a transmitting wirelesscommunication device and a receiving wireless communication device pair.The instructions may further include instructions for receiving one ormore physical (PHY) frame preamble training fields transmitted bywireless communication devices in a listening range of the sensordevice, extracting second channel response information from each of theone or more PHY frame preamble training fields, and associating thesecond channel response information from each of the one or more PHYframe preamble training fields to its respective wireless communicationlink. The instructions may further include instructions for combiningthe first channel response information and the second channel responseinformation for each wireless link in the remote environment, anddetecting motion of an object in the remote environment by analyzing thecombination of the first and second channel response information foreach wireless link in the remote environment, such as through one ormore of the operations as described in FIGS. 3A to 3E, 4, 5,6 or in theexample process 700 shown in FIG. 7.

The example power unit 840 provides power to the other components of thewireless communication device 800. For example, the other components mayoperate based on electrical power provided by the power unit 840 througha voltage bus or other connection. In some implementations, the powerunit 840 includes a battery or a battery system, for example, arechargeable battery. In some implementations, the power unit 840includes an adapter (e.g., an AC adapter) that receives an externalpower signal (from an external source) and coverts the external powersignal to an internal power signal conditioned for a component of thesensor device 800. The power unit 820 may include other components oroperate in another manner.

FIG. 10A is a diagram showing example downlink and uplink transmissionsin the example wireless communication network system 200. The wirelessdevices 220A, 220B, 220C, 220D, having gone through an association andauthentication phase with the AP 230, are wirelessly connected to and incommunication with the AP 230. Wireless signals may be transmitted fromthe AP 230 to the wireless devices 220A, 220B, 220C, 220D via a downlinktransmission 1002. Wireless signals may be transmitted from the wirelessdevices 220A, 220B, 220C, 220D to the AP 230 via respective uplinktransmissions 1004A, 1004B, 1004C, 1004D. In some instances, thelistening devices 250-1, 250-2 can eavesdrop on the downlinktransmission 1002 and the uplink transmissions 1004A, 1004B, 1004C,1004D. Additionally, each of the wireless devices 220A, 220B, 220C, 220Dcan receive (e.g., eavesdrop on) a downlink transmission 1002 from theAP 230 and addressed to another one of the wireless devices 220A, 220B,220C, 220D, and can receive (e.g., eavesdrop on) an uplink transmissionfrom another one of the wireless devices 220A, 220B, 220C, 220D to theAP 230.

The wireless devices 220A, 220B, 220C, 220D and the AP 230 cancommunicate with one another via RF signals, for example, according tothe IEEE 802.11ax standard. A draft of the IEEE 802.11ax standard ispublished in a document entitled “P802.11ax/D8.0, Oct 2020-IEEE ApprovedDraft Standard for Information technology—Telecommunications andinformation exchange between systems Local and metropolitan areanetworks—Specific requirements Part 11: Wireless LAN Medium AccessControl (MAC) and Physical Layer (PHY) Specifications Amendment 1:Enhancements for High Efficiency WLAN,” which was approved by theIEEE-SA Standards Board in February 2021, accessible athttps://ieeexplore.ieee.org/servlet/opac?punumber=9248708, and herebyincorporated by reference in its entirety.

In the IEEE 802.11ax standard, the respective uplink transmissions1004A, 1004B, 1004C, 1004D can be an uplink-orthogonalfrequency-division multiple access (UL-OFDMA) transmission from thewireless devices 220A, 220B, 220C, 220D to the AP 230. A UL-OFDMAtransmission is a feature of the so-called “High-Efficiency LongTraining Field” PHY frame, also known as HE-PHY (e.g., in the Wi-Fi 6standard, according to the IEEE 802.11ax standard).

In a UL-OFDMA transmission, the wireless devices 220A, 220B, 220C, 220Dtransmit respective HE-PHY frames to the AP 230 simultaneously. In someimplementations, simultaneous transmission of the respective HE-PHYframes can include a transmission in parallel at approximately the sametime. In some instances, the simultaneous transmission of the respectiveHE-PHY frames can start or end at the same time (e.g., at exactly thesame time); however, in other implementations, the simultaneoustransmission of the respective HE-PHY frames can partially or fullyoverlap in time with each other, even if they are not preciselysynchronized.

The simultaneous transmission of respective HE-PHY frames from thewireless devices 220A, 220B, 220C, 220D to the AP 230 can occur becausethe wireless devices 220A, 220B, 220C, 220D are assigned respective setsof OFDM subcarriers for their respective PHY frames. In some instances,the respective sets of OFDM subcarriers are referred to as respectiveresource units (RUs). In some instances, beamforming may also be usedfor the UL-OFDMA transmission, thus resulting in an UL-OFDMA withmulti-user MIMO (MU-MIMO) transmission.

FIG. 11A shows spectrum allocation 1100 in an example orthogonalfrequency-division multiplexing (OFDM) scheme. FIG. 11B shows spectrumallocation 1102 in an example orthogonal frequency-division multipleaccess (OFDMA) scheme. In FIGS. 11A and 11B, the vertical axes representall available frequency subcarriers in a wireless communication channel(e.g., in arbitrary units such as subcarrier index, frequency, etc.),and the horizontal axes represent time (e.g., in arbitrary units). Asseen in FIG. 11A, in an OFDM scheme, all available frequency subcarriersof the wireless communication channel (e.g., shown as channel bandwidthBW in the vertical axis) are allocated to a single user (shown in FIG.11A as “User A”). Consequently, the single user uses the entire channelbandwidth BW in an OFDM scheme. In contrast, as seen in FIG. 11B, in anOFDMA scheme, the entire channel bandwidth BW is divided into respectivesubsets of subcarriers, or resource units (RUs) 1104A, 1104B, 1104C,1104D. The respective RUs are allocated to different users. In an OFDMAscheme, multiple users can therefore communicate on the wirelesscommunication channel simultaneously using their respective RUs. In theexample of FIG. 11B, all available frequency subcarriers are dividedinto a first resource unit 1104A, a second resource unit 1104B, a thirdresource unit 1104C, and a fourth resource unit 1104D. In someinstances, the resource units 1104A, 1104B, 1104C, 1104D do not overlapin frequency and are allocated to respective, different users (e.g.,User A, User B, User C, and User D, respectively). Consequently, theOFDMA scheme results in frequency multiplexing or spectrum sharing(e.g., a fine-grain spectrum sharing) among different users.

FIG. 11C is a diagram showing an example sequence of HE-PHY framestransmitted in an example wireless communication network systemoperating according to the IEEE 802.11ax standard. The vertical axisrepresents all available frequency subcarriers in a wirelesscommunication channel (e.g., in arbitrary units such as subcarrierindex, frequency, etc.), and the horizontal axis represents time (e.g.,in arbitrary units). In implementations where the wireless communicationnetwork system 200 shown in FIG. 10A operates according to the IEEE802.11ax standard, the AP 230 may perform a downlink transmission 1002that sends a first downlink (DL) HE-PHY frame 1106 to the wirelessdevices 220A, 220B, 220C, 220D. The first DL HE-PHY frame 1106 elicits aUL-OFDMA transmission 1108 from the wireless devices 220A, 220B, 220C,220D to the AP 230. FIG. 11C also shows a second DL HE-PHY frame 1110that is transmitted from the AP 230 to the wireless devices 220A, 220B,220C, 220D after the UL-OFDMA transmission 1108.

The first HE-PHY frame 1106 can include a preamble and a trigger frame,and can be addressed to the wireless devices 220A, 220B, 220C, 220D. Insome instances, the trigger frame includes a triggered responsescheduling (TRS) control field, which can be used by the AP 230 toallocate respective RUs to the wireless devices 220A, 220B, 220C, 220D.The TRS control field can also be used by the AP 230 to specify a set ofparameters for the subsequent UL-OFDMA transmission 1108 from thewireless devices 220A, 220B, 220C, 220D to the AP 230. In someinstances, the set of parameters can include the duration of theUL-OFDMA transmission 1108, the target RSSI for the UL-OFDMAtransmission 1108 (e.g., as measured at the AP 230), or thehigh-efficiency modulation and coding scheme of the UL-OFDMAtransmission 1108. Other parameters for the subsequent UL-OFDMAtransmission 1108 can also be specified in the TRS control field.

In response to receiving and processing the first DL HE-PHY frame 1106,the wireless devices 220A, 220B, 220C, 220D perform respective uplinktransmissions 1004A, 1004B, 1004C, 1004D that transmit the UL-OFDMAtransmission 1108 to the AP 230. The UL-OFDMA transmission 1108 istransmitted in accordance with the RU allocation and the parametersspecified in the trigger frame of the first DL HE-PHY frame 1106. Insome instances, such as in the example shown in FIG. 11C, transmissionof the UL-OFDMA transmission 1108 commences one short interframe space(SIFS) time period after the end of the first DL HE-PHY frame 1106. Inthe most common instances, the SIFS time period may be in a range fromabout 3 us to about 16 μs, and can be defined by the physical layer andfrequency band used. An HE-PHY, for example, defines the SIFS time to beabout 10 us in the 2.4 GHz band and about 16 μs in the 5 GHz and 6 GHzbands. As seen in FIG. 11D, the UL-OFDMA transmission 1108 can includerespective HE-PHY frames 1108A, 1108N that are simultaneouslytransmitted from the wireless devices to which the first DL HE-PHY frame106 was addressed (e.g., wireless devices 220A, 220B, 220C, 220D). TheHE-PHY frames 1108A, 1108N of the UL-OFDMA transmission 1108 can includerespective preambles and respective uplink block acknowledgements.

Since the UL-OFDMA transmission 1108 allows the wireless devices 220A,220B, 220C, 220D to transmit respective HE-PHY frames to the AP 230simultaneously, a single UL-OFDMA transmission 1108 can be used todetect motion in multiple motion detection zones simultaneously. FIG.10B is a diagram showing example motion detection zones in an examplewireless communication network system. As an example, the UL-OFDMAtransmission 1108 may include a transmission of the HE-PHY frame 1108Afrom the wireless device 220A to the AP 230 and a simultaneoustransmission of the HE-PHY frame 1108N from the wireless device 220D tothe AP 230. The HE-PHY frames 1108A, 1108N can be used (e.g., by thelistening device 250-1, the listening device 250-2, or some other devicethat receives the UL-OFDMA transmission 1108) to compute respectivechannel responses. A channel response can correspond to a physical pathbetween the wireless device transmitting the HE-PHY frame and the devicereceiving the HE-PHY frame. Consequently, in examples where thelistening device 250-1 eavesdrops on the transmissions in the wirelesscommunication network system 200 and computes the respective channelresponses, the channel response computed from the HE-PHY frame 1108A maybe indicative of the physical path between the wireless device 220A andthe listening device 250-1, while the channel response computed theHE-PHY frame 1108N may be indicative of the physical path between thewireless device 220D and the listening device 250-1. The channelresponses computed from the HE-PHY frames 1108A, 1108N can be used tosimultaneously probe a first motion detection zone 1006A and a secondmotion detection zone 1006D, respectively. Stated differently, in someinstances, the channel responses computed from the HE-PHY frames 1108A,1108N may be used to generate motion data that can be used tosimultaneously detect whether motion has occurred in motion detectionzones 1006A, 1006D.

The second DL HE-PHY frame 1110 can include a preamble and a multi-user(MU) block acknowledgement, and can be addressed to the wireless devices220A, 220B, 220C, 220D. In some instances, the MU block acknowledgementof the second HE-PHY frame 1110 can be used by the AP 230 to acknowledgereceipt of the UL-OFDMA transmission 1108. In some instances, such as inthe example shown in FIG. 11C, transmission of the second DL HE-PHYframe 1110 commences one SIFS time period (e.g., about 16 us in 5 GHzand 6 GHz bands) after the end of UL-OFDMA transmission 1108.

In some instances, each of the first DL HE-PHY frame 1106, the UL-OFDMtransmission 1108, and the second DL HE-PHY frame 1110 can include a MAClayer frame encoded within (e.g., encapsulated within) the data payloadof an HE-PHY frame, analogous to the example shown in FIG. 9. At the PHYlayer, data can be referred to as a physical layer (PHY) protocol dataunit (PPDU), which can be a unit of data exchanged between two peer PHYentities to provide the PHY data service. The PPDU can include apreamble followed by a payload. The payload can include digital data,provided by the MAC layer, that has gone through a coding and mappingprocess to produce an OFDM vector (using defined rates and bandwidths).

In some implementations, HE-PHY frames can have one of a plurality ofPPDU formats, including a High-Efficiency Single-User PPDU (HE SU PPDU)format, a High-Efficiency Trigger-Based PPDU (HE TB PPDU) format, aHigh-Efficiency Multi-User PPDU (HE MU PPDU) format, and aHigh-Efficiency Enhanced-Range PPDU (HE ER PPDU) format.

FIG. 12A shows an example HE-PHY frame 1200 having the HE SU PPDUformat.

In some instances, the HE-PHY frame 1200 can be used to carry a singleMAC data payload (on an uplink transmission or a downlink transmission).The first DL HE-PHY frame 1106 discussed above in relation to FIG. 11Ccan be a HE-PHY frame having the HE SU PPDU format, and as discussed infurther detail below, the AP 230 can coordinate a UL-OFDMA transmissionfrom the wireless devices 220A, 220B, 220C, 220D using a trigger requestin a trigger frame. In some instances, the trigger frame can be a MAClayer frame encoded within the data payload 1202 of the HE-PHY frame1200. In some instances, the trigger frame allocates a respective subsetof available bandwidth (e.g., allocates respective RUs) or spatialstreams (e.g., allocates respective beamforming matrices) to thewireless devices 220A, 220B, 220C, 220D. The trigger frame can alsospecify a set of parameters for the subsequent UL-OFDMA transmission.

In some instances, a HE-PHY frame having the HE MU PPDU format can beused to carry multiple MAC data payloads to the wireless devices 220A,220B, 220C, 220D using the downlink transmission 1002. The multiple MACdata payloads are transmitted to the wireless devices 220A, 220B, 220C,220D at the same time (e.g., simultaneously). To allow for thesimultaneous transmission of multiple MAC data payloads to the wirelessdevices 220A, 220B, 220C, 220D, the data payloads can be multiplexed onthe downlink transmission 1002 by frequency (e.g., using an OFDMAscheme) or by spatial stream (e.g., by beamforming).

In some instances, a HE-PHY frame having the HE ER PPDU format has aHE-SIG-A field that is twice the duration of the HE-SIG-A field in aHE-PHY frame having the HE SU PPDU format. The HE-PHY frame having theHE ER PPDU format can be used to carry a single MAC data payload.

FIG. 12B shows an example HE-PHY frame 1201 having the HE TB PPDUformat.

In some instances, the HE-PHY frame 1201 can be used by the wirelessdevices 220A, 220B, 220C, 220D to respond to the trigger request fromthe AP 230. As such, in some instances, the UL-OFDMA transmission 1108discussed above in relation to FIG. 11C can include multiple HE-PHYframes having the HE TB PPDU format. Each of the respective HE-PHYframes 1108A, 1108N of the UL-OFDMA transmission 1108 can be used tocarry a single MAC data payload (per respective transmitting user). Asseen in the examples of FIGS. 12A and 12B, the duration of theHigh-Efficiency Short Training Field (HE-STF) 1213 of the HE-PHY frame1201 having the HE TB PPDU format can be twice that the duration of theHE-STF 1204 of the HE-PHY frame 1200 having the HE SU PPDU format.

As seen in FIG. 12B, the HE-PHY frame 1201 having the HE TB PPDU formatincludes multiple fields, including pre-HE modulated fields and HEmodulated fields. The pre-HE modulated fields include the legacy shorttraining field (L-STF) 1203, the legacy long training field (L-LTF)1205, the legacy signal (L-SIG) field 1207, the RL-SIG field 1209, andthe HE-SIG-A field 1211. The HE modulated fields include the HE-STF1213, and the High-Efficiency Long Training Field (HE-LTF) 1215. Any ofthe fields in the HE-PHY frame 1201 can be used to compute therespective channel responses corresponding to the respective motiondetection zones. In some implementations, the HE-LTF 1215 can be used tocompute the respective channel responses corresponding to the respectivemotion detection zones. Using the HE-LTF 1215 of the HE-PHY frame 1201to compute the respective channel responses may provide one or moreadvantages in some instances. For example, the HE-LTF 1215 of the HE-PHYframe 1201 activates the largest number of subcarriers (e.g., comparedto other fields in the HE-PHY frame 1201), thereby providing the maximumavailable continuous measurement bandwidth for computing the respectivechannel responses.

An example HE-LTF is described on page 620 of the draft of the IEEE802.11ax standard as follows:

In a 20 MHz transmission the 4x HE-LTF sequence transmitted onsubcarriers [−122: 122] is given by Equation (27-42).

$\begin{matrix}{{HELTF}_{{- 122},122} = \left\{ {{- 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{+ 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},0,0,0,{- 1},{+ 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{+ 1},{+ 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{+ 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{- 1},{+ 1},{+ 1},{+ 1},{+ 1},{- 1},{- 1},{+ 1},{+ 1},{+ 1},{+ 1},{+ 1},{- 1},{+ 1},{+ 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{- 1},{- 1},{+ 1},{- 1},{+ 1},{- 1},{+ 1},{+ 1}} \right\}} & \left( {27\text{-}42} \right)\end{matrix}$

When responding to the trigger frame, the wireless devices 220A, 220B,220C, 220D transmit the portions of the HE-LTF 1215 within theirrespective, allocated RUs. In some instances, all subcarriers in RUs notallocated to a respective wireless device 220A, 220B, 220C, 220D can beset to zero.

FIG. 13A shows example resource unit allocations for a HE-PHY frame 1201having the HE TB PPDU format transmitted over a channel having abandwidth of 20 MHz. FIG. 13B shows example resource unit allocationsfor a HE-PHY frame 1201 having the HE TB PPDU format transmitted over achannel having a bandwidth of 40 MHz. FIG. 13C shows example resourceunit allocations for a HE-PHY frame 1201 having the HE TB PPDU formattransmitted over a channel having a bandwidth of 80 MHz. The RUallocations shown in FIGS. 13A to 13C illustrate the number of 20 MHzchannels that may be modulated for the pre-HE modulated fields for eachRU size and location in a HE-PHY frame 1201 having the HE TB PPDUformat. The horizontal axis of the example RU allocations representsfrequency subcarriers (e.g., in arbitrary units such as subcarrierindex, frequency, etc.).

In the example shown in FIG. 13A, the 20 MHz channel can include 242subcarriers. In some instances, the 20 MHz channel may include a singleRU of 242 subcarriers (e.g., as shown in allocation 1300); two RUs, eachhaving 106 subcarriers (e.g., as shown in allocation 1302); four RUs,each having 52 subcarriers (e.g., as shown in allocation 1304); or nineRUs, each having 26 subcarriers (e.g., as shown in allocation 1306). Insome instances, some subcarriers are designated as guard intervals(e.g., as shown in allocations 1304 and 1306). In the exampleallocations shown in FIG. 13A, the RUs are located in one 20 MHzchannels, thus needing 20 MHz pre-HE modulated fields.

In the example shown in FIG. 13B, the 40 MHz channel can include 484subcarriers. In some instances, the 40 MHz channel may include a singleRU of 484 subcarriers (e.g., as shown in allocation 1301). In theallocation 1301, the RU is located in two 20 MHz channels, thus needing40 MHz duplicated pre-HE modulated fields. In some instances, the 40 MHzchannel may include two RUs, each having 242 subcarriers (e.g., as shownin allocation 1303); four RUs, each having 106 subcarriers (e.g., asshown in allocation 1305); eight RUs, each having 52 subcarriers (e.g.,as shown in allocation 1307); or eighteen RUs, each having 26subcarriers (e.g., as shown in allocation 1309). In some instances, somesubcarriers are designated as guard intervals (e.g., as shown inallocations 1305, 1307, and 1309).

In the example shown in FIG. 13C, the 80 MHz channel can include 996subcarriers. In some instances, the 80 MHz channel may include a singleRU of 996 subcarriers (e.g., as shown in allocation 1310). In theallocation 1310, the RU is located in four 20 MHz channels, thus needing80 MHz duplicated pre-HE modulated fields. In some instances, the 80 MHzchannel may include two RUs, each having 484 subcarriers (e.g., as shownin allocation 1320); four RUs, each having 242 subcarriers (e.g., asshown in allocation 1330); eight RUs, each having 106 subcarriers (e.g.,as shown in allocation 1340); sixteen RUs, each having 52 subcarriers(e.g., as shown in allocation 1350); or 37 RUs, each having 26subcarriers (e.g., as shown in allocation 1360). In some instances, somesubcarriers are designated as guard intervals (e.g., as shown inallocations 1340, 1350, and 1360).

In the HE-PHY frame 1201 having the HE TB PPDU format, the pre-HEmodulated fields (e.g., the L-STF 1203, the L-LTF 1205, the L-SIG field1207, the RL-SIG field 1209, the HE-SIG-A field 1211) are sent on 20 MHzchannels where the HE modulated fields of the respective wirelessdevices 220A, 220B, 220C, 220D are located. Consequently, when HEmodulated fields are located in more than one 20 MHz channel (e.g., asseen in the examples shown in FIGS. 13B and 13C), the pre-HE modulatedfields may need to be duplicated over the multiple 20 MHz channels. FIG.14 shows an example transmitter block diagram 1400 for the pre-HEmodulated fields of the HE-PHY frame 1201 having the HE TB PPDU format.The transmitter block 1400 includes a single spatial stream, which, insome instances, includes block convolution code (BCC) encoder 1402, aBCC interleaver 1404, a constellation mapper 1406, a filter 1408, and aninverse Discrete Fourier transform (IDFT) block 1410. The transmitter1400 also includes multiple transmit chains. The number of transmitchains can be equal to the number of transmit antennas, N_(TX).

The BCC encoder 1402 operates on input data and can be a convolutionencoder using industry standard polynomials g0=133(8), g1=171(8) andrate=1/2. In some instances, higher encoding rates of 2/3 and 3/4 can beachieved via puncturing. The BCC interleaver 1404 performs a bitrotation process that operates on a block size equal to the number ofbits in a single OFDM symbol. In some instances, the interleavingperformed by the BCC interlever 1404 can be performed in two operations,where first adjacent coded bits are mapped onto non-adjacentsubcarriers, and secondly adjacent coded bits are mapped in analternating fashion onto less/more significant bits of theconstellation. The constellation mapper 1406 performs a mapping processthat takes the BCC Encoded and Interleaved signal, and determines thecomplex (e.g., in-phase (I) and quadrature-phase (Q)) subcarriermodulation. For each OFDM subcarrier, a group of bits corresponding tothe QAM order (e.g, 16-QAM takes 4 bits, 64-QAM takes 6 bits, where2{circumflex over ( )}bits=QAM order) is used to represent the amplitudeof both the I and Q components of the modulation based on apre-determined constellation encoding. For cases of the non-MIMO fieldsof an HE PPDU of FIG. 12A and FIG. 12B (e.g., L-STF, L-LTF, L-SIG,RL-SIG, HE-SIG-A), the filter 1408 can be used to transmit data on all20 MHz channels of which the assigned RU is located within. The IDFTblock 1410 can be used to obtain the time-domain waveform (e.g., thecomplex, IQ time-domain waveform) of the modulated signal (e.g., thecomplex, IQ, modulated signal).

The transmitter block 1400 can include multiple transmit chains. Some ofthe multiple transmit chains can include a cyclic shift for Diversity(CSD) per chain block 1412, an insert guard interval (GI) and windowblock 1414, and an analog and RF block 1416. The CSD per chain block1412 can be applied on transmitters which contain multiple outputantennas. In some instances, for non-MIMO fields of an HE PPDU of FIG.12A and FIG. 12B (e.g., L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A), the samedata is transmitted on all N_(TX) transmit antennae. However, to avoidthe potential of NULLs being created due to the superposition, a cyclicshift in the range of hundreds of nanoseconds can be applied to eachtransmit antenna to decrease the potential of NULLs being formed. Theinsert GI and window block 1414 can be used to insert the appropriateguard interval into the signal and to truncate the periodic waveform tothe length of a single OFDM symbol by applying time-domain windowing.The analog and RF block 1416 can be used to convert the complex digitalbaseband signal to an in-phase and a quadrature-phase analog signal, andto up-convert to RF according to the center frequency of the desiredchannel.

As discussed above, the trigger frame can be a MAC layer frame encodedwithin the data payload 1202 of the HE-PHY frame 1200 having the HE SUPPDU format. At the MAC layer, data can be referred to as a media accesscontrol (MAC) protocol data unit (MPDU), which can be a unit of dataexchanged between two peer MAC entities using the services of thephysical (PHY) layer. In some instances, an MPDU can also be referred toas a medium access control (MAC) frame. The MPDU can include a preamblefollowed by a payload. Both the preamble and payload can be digitaldata, represented in binary format.

FIG. 15 shows an example format of a trigger frame 1500. The triggerframe 1500 includes a frame control field 1502, a common informationfield 1504, and a user information list field 1506. FIG. 16 shows anexample expansion of the frame control field 1502 of the trigger frame1500. FIG. 17 shows an example expansion of the common information field1504 of the trigger frame 1500. FIG. 18 shows an example expansion ofthe user information list field 1506 of the trigger frame 1500. As seenin FIG. 16, the frame control field 1502 includes a type field 1600, asubtype field 1602, and a protected frame field 1604. In some instances,a trigger frame for a subsequent UL-OFDMA transmission can be identified(e.g., by the wireless devices 220A, 220B, 220C, 220D) based on theframe control field 1502 (e.g., the binary value in the type field 1600and in the subtype field 1602). For example, a trigger frame for asubsequent UL-OFDMA transmission can be identified by type field 1600 ofthe frame control field 1502 having a binary value 01 and subtype field1602 of the frame control field 1502 having binary value 0010 (e.g.,Type=01 indicates a control frame, and Subtype=0010 indicates a triggerframe). Additionally, the frame control field 1502 can be transmitted asa non-protected transmission (e.g., without encryption), allowing theHE-PHY frame 1200 having the HE SU PPDU format to be processed by anexternal party not associated to the network (e.g., the listeningdevices 250-1, 250-2). The protected field frame 1604 can be set to abinary value of 1 in instances where at least one of the following areused: data frames protected using the mechanisms specified in Clause 12(Security) of the draft of the IEEE 802.11ax standard; individuallyaddressed protected robust management frames; or authentication frameswith Authentication Algorithm Number field equal to 1 (e.g., indicatinga shared key) and Authentication Transaction Sequence Number field equalto 3. The protected field frame 1404 can be set to a binary value of 0in all other instances.

The common information field 1504 can contain configuration informationthat is common to all the wireless devices 220A, 220B, 220C, 220Dresponding to the trigger frame 1300 from the AP 230. As seen in FIG.17, the common information field 1504 includes an uplink bandwidth (ULBW) field 1700, a guard interval (GI) and HE-LTF type field 1702, aMU-MIMO HE-LTF mode field 1704, a number of HE-LTF symbols and midambleperiodicity field 1706, and a doppler field 1708.

In some instances, the UL BW field 1700 specifies the entire bandwidthof all available frequency subcarriers of the wireless communicationchannel (e.g., the entire bandwidth BW shown in FIGS. 11A and 11B). TheRUs allocated to the respective wireless devices 220A, 220B, 220C, 220Dare subsets of the entire bandwidth. In some instances, the entirebandwidth can be 20 MHz, 40 MHz, 80 MHz, or 160 MHz. In someimplementations, the 160 MHz channel can include a primary 80 MHzchannel and a secondary 80 MHz channel. The binary value indicated bythe UL BW field 1700 can indicate the entire bandwidth of all availablefrequency subcarriers of the wireless communication channel. As anexample, a binary value of 00 in the UL BW field 1700 can indicate a 20MHz channel bandwidth (e.g., a 20 MHz PPDU), a binary value of 01 in theUL BW field 1700 can indicate a 40 MHz channel bandwidth (e.g., a 40 MHzPPDU), a binary value of 10 in the UL BW field 1700 can indicate a 80MHz channel bandwidth (e.g., a 80 MHz PPDU), and a binary value of 11 inthe UL BW field 1700 can indicate a 160 MHz channel bandwidth (e.g., a160 MHz PPDU).

As seen in FIG. 18, the user information list field 1506 includes aresource unit (RU) allocation field 1800. The RU allocation field 1800along with the UL BW field 1700 can identify the size and location ofthe RUs allocated to the respective wireless devices 220A, 220B, 220C,220D. In some instances, when the UL BW field 1700 indicates a 20 MHz,40 MHz, or 80 MHz PPDU, then B0 (e.g., the first bit) of the RUallocation field 1600 can be set to 0. In instances where the UL BWfield 1700 indicates a 160 MHz PPDU, then B0 of the RU allocation field1800 can be set to 0 to indicate that the RU allocation applies to theprimary 80 MHz channel and set to 1 to indicate that the RU allocationapplies to the secondary 80 MHz channel.

The second to eighth bits (e.g., B1-B7) of RU allocation field 1800 canbe encoded to identify which RU and bandwidth is assigned for thesubsequent UL-OFDMA transmission. Table 1 shows example encodings thatcan be used for the second to eighth bits of the RU allocation field1800.

TABLE 1 B7 to B1 of the RU allocation field B7-B1 of the RU AllocationRU subfield UL BW subfield size RU Index 0-8 20 MHz, 40 MHz, 80 MHz,  26RU1 to RU9, 80 + 80 MHz or 160 MHz respectively  9-17 40 MHz, 80 MHz,80 + 80 RU10 to RU18, MHz or 160 MHz respectively 18-36 80 MHz, 80 + 80MHz or RU19 to RU37, 160 MHz respectively 37-40 20 MHz, 40 MHz, 80 MHz, 52 RU1 to RU4, 80 + 80 MHz or 160 MHz respectively 41-14 40 MHz, 80MHz, 80 + 80 RU5 to RU8, MHz or 160 MHz respectively 45-52 80 MHz, 80 +80 MHz or RU9 to RU16, 160 MHz respectively 53, 54 20 MHz, 40 MHz, 80MHz, 106 RU1 to RU2, 80 + 80 MHz or 160 MHz respectively 55, 56 40 MHz,80 MHz, 80 + 80 RU3 to RU4, MHz or 160 MHz respectively 57-60 80 MHz,80 + 80 MHz or RU5 to RU8, 160 MHz respectively 61 20 MHz, 40 MHz, 80MHz, 242 RU1 80 + 80 MHz or 160 MHz 62 40 MHz, 80 MHz, 80 + 80 RU2 MHzor 160 MHz 63, 64 80 MHz, 80 + 80 MHz or RU3 to RU4, 160 MHzrespectively 65 40 MHz, 80 MHz, 80 + 80 484 RU1 MHz or 160 MHz 66 80MHz, 80 + 80 MHz or RU2 160 MHz 67 80 MHz, 80 + 80 MHz or 996 RU1 160MHz 68 80 + 80 MHz or 160 MHz 2 × 996 RU1

As seen in Table 1, if the UL BW field indicates a 160 MHz PPDU, thedescription indicates the RU index for the primary 80 MHz channel orsecondary 80 MHz channel, as indicated by the first bit (B0) of the RUallocation field 1800.

The GI and HE-LTF type field 1702 of the common information field 1504can be used to specify, to the wireless devices 220A, 220B, 220C, 220D,the HE-LTF type and guard interval that the respective wireless devices220A, 220B, 220C, 220D are to be uses when transmitting the HE TB PPDUresponse. The HE-LTF type indicates a duration of the HE-LTF symbol,with a 1x HE-LTF type corresponding to an HE-LTF symbol duration of 3.2μs, a 2x HE-LTF type corresponding to an HE-LTF symbol duration of 6.4μs, and a 4x HE-LTF type corresponding to an HE-LTF symbol duration of12.8 μs. Table 2 shows example encodings that can be used for the GI andHE-LTF type field 1702.

TABLE 2 GI and HE-LTF type field encoding GI and HE-LTF type field valueDescription 0 1x HE-LTF + 1.6 μs GI 1 2x HE-LTF + 1.6 μs GI 2 4xHE-LTF + 3.2 μs GI 3 Reserved

The information in the GI and HE-LTF type field 1702 can be used whencomputing the respective channel responses, since the encoding of the GIand HE-LTF type field 1702 can determine the number of frequency pointsand spacing of the excited subcarriers in the HE-LTF, and thus thefrequency resolution of the respective channel responses.

The MU-MIMO HE-LTF mode field 1704 of the common information field 1504can be used to specify the HE-LTF mode as either single-streamed ormasked, using the encoding in Table 3.

TABLE 3 MU-MIMO HE-LTF mode field encoding MU-MIMO HE-LTF mode fieldvalue Description 0 HE single stream pilot HE-LTF mode 1 HE maskedHE-LTF sequence mode

The trigger frame 1500 can indicate whether the uplink multi-usertransmission following it uses HE single stream pilot HE-LTF mode or HEmasked HE-LTF sequence mode if the HE-LTF type of the HE TB PPDU is 2xHE-LTF or 4 x HE-LTF. A HE, no pilot HE-LTF mode is used if the HE-LTFtype of the HE TB PPDU is 1x HE-LTF. If the HE single stream pilotHE-LTF mode is used, no masking is applied to the HE-LTF. The HE singlestream pilot HE-LTF mode can be used for any UL-OFDMA transmission,including UL-OFDMA with MU-MIMO transmissions.

The HE-LTF field allows the device receiving the HE TB PPDU to estimatethe channel (e.g., MIMO channel) between the set of constellation mapperoutputs (e.g., seen in FIG. 14) and the receiving device's receivechain. If space-time block coding (STBC) is applied, the HE-LTF fieldallows the device receiving the HE TB PPDU to estimate the channel(e.g., MIMO channel) between the STBC encoder outputs and the receivingdevice's receive chain. In an HE TB PPDU, the transmitter of a user u inthe r^(th) RU provides training for N_(STS.r.u) space-time streams(e.g., defined in the draft of the IEEE 802.11ax standard) used for thetransmission of a PLCP Service Data Unit (PSDU). For each subcarrier inthe r^(th) RU, the MIMO channel that can be estimated is aN_(RX)×N_(STS.r.total) matrix (e.g., defined in the draft of the IEEE802.11ax standard). When a single stream pilot is used in the HE-LTF,the pilot subcarriers of each HE-LTF symbol can be multiplied by theentries of a matrix R_(HE-LTF) (e.g., defined in the draft of the IEEE802.11ax standard) to allow the device receiving the HE TB PPDU to trackphase or frequency offset (or both) when using the HE-LTF to compute thechannel responses. In some instances, single stream pilots can be usedin the HE-LTF field for single user uplink and downlink OFDMA, as wellas for downlink MU-MIMO and partial bandwidth uplink MU-MIMOtransmissions. In some implementations, single stream pilots can be usedin the HE-LTF field for a full bandwidth uplink MU-MINO transmission ifsingle stream pilot HE-LTF mode is selected.

The doppler field 1708 of the common information field 1504 allows thetransmitter of the trigger frame 1500 (e.g., the AP 230) to request thewireless devices 220A, 220B, 220C, 220D to periodically include a“midamble” within the data transmission. The midamble can be an HE-LTFinserted periodically within the transmission (e.g., to allow the devicereceiving the HE TB PPDU to re-equalize for a rapidly changing channeldue to a high Doppler presence). If multiple midambles are present inthe transmission of the HE TB PPDU, the channel responses can becomputed multiple times per transmission of the HE TB PPDU. If thedoppler field 1708 is enabled (e.g., set to 1), the number of HE-LTFsymbols and midamble periodicity field 1706 of the common informationfield 1504 can be used to indicate how frequently the midamble isincluded within the data transmission.

As seen in FIG. 18, the user information list field 1506 includes anassociation identifier (AID12) field 1802. When the wireless devices220A, 220B, 220C, 220D connect to the AP 230 (e.g., via anauthentication and association phase), each of the wireless devices220A, 220B, 220C, 220D is assigned a unique identifier, which isindicated as a 12-bit identifier in the AID12 field 1802. In someinstances, the device receiving the trigger frame 1500 (e.g., listeningdevices 250-1, 250-2 or any other device) can use the AID12 field 1802in the trigger frame 1500 to identify the wireless devices 220A, 220B,220C, 220D connected to the AP 230. Table 4 shows example encodings ofthe AID12 field 1802.

TABLE 4 AID12 field encoding AID12 subfield Description   0 User Infofield allocates one or more contiguous RA-RUs for associated wirelessdevices   1-2007 User Info field is addressed to an associated wirelessdevice whose AID is equal to the value in the AID12 subfield 2008-2044Reserved 2045 User Info field allocates one or more contiguous RA-RUsfor unassociated wireless devices 2046 Unallocated RU 2047-4094 Reserved4095 Start of Padding FieldAs seen in Table 4, AID12 values between (and including) 1 and 2007 canbe used by the device receiving the trigger frame 1500 (e.g., listeningdevices 250-1, 250-2 or any other device) to identify the wirelessdevices 220A, 220B, 220C, 220D connected to the AP 230.

As seen in FIG. 18, the user information list field 1506 includes anuplink (UL) target receive power field 1804. In some instances, the ULtarget receive power field 1804 can indicate, to the wireless devices220A, 220B, 220C, 220D, the target RSSI for the subsequent UL-OFDMAtransmission (e.g., as measured at the AP 230). In some instances,indicating the target RSSI to the wireless devices 220A, 220B, 220C,220D allows the wireless devices 220A, 220B, 220C, 220D to adjust theirrespective transmit power levels when transmitting their respectiveHE-PHY frames, such that the received power levels are substantiallyequal at the AP 230. Use of the UL target receive power field 1804 toset the target RSSI for the subsequent UL-OFDMA transmission canovercome a limited dynamic range at the AP 230 and can substantiallyeliminate the near/far effect of different transmitters (e.g., theeffect the wireless devices 220A, 220B, 220C, 220D being located atdifferent distances from the AP 230). For example, without the UL targetreceive power field 1804, a HE-PHY frame transmitted from a wirelessdevice in close proximity to the AP 230 can have a received power level(e.g., at the AP 230) that is greater than that of a HE-PHY frametransmitted from a wireless device farther from the AP 230.Consequently, without the UL target receive power field 1804, in anUL-OFDMA transmission where the respective HE-PHY frames are transmittedsimultaneously, the HE-PHY frame from a closer wireless device canobscure reception of the HE-PHY frame from a farther wireless device.Consequently, use of the UL target receive power field 1804substantially eliminates the effect the wireless devices 220A, 220B,220C, 220D being located at different distances from the AP 230, sinceeach of the wireless devices 220A, 220B, 220C, 220D adjusts theirrespective transmit power levels when transmitting their respectiveHE-PHY frames, such that the received power levels are substantiallyequal at the AP 230.

FIG. 19 is a diagram showing a flowchart for an example process 1900 forcomputing channel responses in a wireless communication network systemoperating according to the IEEE 802.11ax standard. The process 1900 canbe performed by one (or both) of the listening devices 250-1, 250-2 tocompute respective channel responses that can be used to simultaneouslydetect whether motion has occurred in respective motion detection zones.Additionally or alternatively, the process 1900 can be performed by oneor more of the wireless devices 220A, 220B, 220C, 220D to simultaneouslydetect whether motion has occurred in respective motion detection zones.The process 1900 may include additional or different operations, and theoperations shown in FIG. 19 may be performed in the order shown or inanother order. In some cases, one or more of the operations shown inFIG. 19 are implemented as processes that include multiple operations,sub-processes for other types of routines. In some cases, operations canbe combined, performed in another order, performed in parallel, iteratedor otherwise repeated or performed in another manner.

At 1902, a DL HE-PHY frame is received. In some instances, the DL HE-PHYframe may be the first DL HE-PHY frame 1106 shown in FIG. 11C and canhave the HE SU PPDU format (e.g., shown in FIG. 12A). The DL HE-PHYframe can include a trigger frame, which, as discussed above, can be aMAC layer frame encoded within the data payload 1202 of the HE-PHY frame1200 having the HE SU PPDU format.

At 1904, a determination is made as to whether the DL HE-PHY frame(e.g., received at 1902) includes a trigger frame for a subsequentUL-OFDMA transmission. Stated differently, at 1904, a determination ismade as to whether the trigger frame in the DL HE-PHY frame (e.g.,received at 1902) can elicit a subsequent UL-OFDMA transmission. Thedevice can determine whether the DL HE-PHY frame includes a triggerframe for a subsequent UL-OFDMA transmission based on the frame controlfield of the trigger frame. For example, as discussed above in relationto FIGS. 15 and 16, a trigger frame can be identified by type field 1600of the frame control field 1502 having a binary value 01 and subtypefield 1602 of the frame control field 1502 having binary value 0010(e.g., Type=01 indicates a control frame, and Subtype=0010 indicates atrigger frame).

In response to a determination that the DL HE-PHY frame is not for asubsequent UL-OFDMA transmission, the process 1900 returns to 1902.Conversely, in response to a determination that the DL HE-PHY frame isfor a subsequent UL-OFDMA transmission, the process 1900 proceeds to1906.

At 1906, multiple fields of the DL HE-PHY frame are parsed and analyzed,for example, to determine a set of parameters of the subsequent UL-OFDMAtransmission. The set of parameters determined at 1906 can be used bythe device that received the DL HE-PHY frame to prepare a radiosubsystem and a baseband subsystem for reception of the subsequentUL-OFDMA transmission. As an example, the set of parameters can beapplied to a radio subsystem or a baseband subsystem (or both) forreception of the subsequent UL-OFDMA transmission.

In some instances, at 1906, the common information field 1504 of thetrigger frame 1500 can be parsed and analyzed to determine one or moreof the following: the total bandwidth of the subsequent UL-OFDMAtransmission (e.g., indicated by the UL BW field 1700 of the commoninformation field); the HE-LTF type and guard interval duration of thesubsequent UL-OFDMA transmission (e.g., indicated by the GI and HE-LTFtype field 1702 of the common information field); the HE-LTF mode of thesubsequent UL-OFDMA transmission (e.g., indicated by the MU-MIMO HE-LTFmode field 1704 of the common information field); or whether and howfrequently a midamble is included within the subsequent UL-OFDMAtransmission (e.g., indicated by the number of HE-LTF symbols andmidamble periodicity field 1706 and the doppler field 1708 of the commoninformation field).

In some instances, at 1906, user information list field 1506 of thetrigger frame 1500 can be parsed and analyzed to determine one or moreof the following: the RU allocation for the respective wireless devicestransmitting the subsequent UL-OFDMA transmission (e.g., indicated bythe RU allocation field 1800 of the user information list field); theidentity of the wireless devices transmitting the subsequent UL-OFDMAtransmission (e.g., indicated by the AID12 field 1802 of the userinformation list field); or the target RSSI for the subsequent UL-OFDMAtransmission (e.g., as measured at the AP 230 and indicated by the ULtarget receive power field 1804 of the user information list field).

At 1908, one SIFS time period (e.g., 16 μs in 5 GHz and 6 GHz bands) isallowed to elapse after the end of the DL HE-PHY frame. At 1910, theUL-OFDMA transmission is received (e.g., from the wireless devicesidentified at 1906, which simultaneously transmit respective HE-PHYframes using the respective RUs identified at 1906). As discussed above,the UL-OFDMA transmission can include multiple HE-PHY frames having theHE TB PPDU format (e.g., as seen in FIG. 12B).

In some instances, the device receiving the UL-OFDMA transmission at1910 (e.g., listening devices 250-1, 250-2 or any other device) may havea high dynamic range, thus allowing the device to overcome the near/fareffect of different transmitters. In other instances (e.g., where thedevice receiving the UL-OFDMA transmission at 1910 has limited dynamicrange), operation 1912 can be performed to filter the respective HE-PHYframes transmitted from the wireless devices and using the RUsidentified at 1906. Operation 1912 can be performed using a filter bankincluded in the receiver chain of the device receiving the UL-OFDMAtransmission.

FIG. 20 shows an example filter bank 2000 that can be used to equalizerespective HE-PHY frames. The filter bank 2000 may be implemented in anyposition along the receive signal chain of the device receiving theUL-OFDMA transmission. In some instances, the filter bank 2000 can beimplemented at the RF front end (e.g., after the antenna). In otherinstances, the filter bank 2000 can be implemented at an intermediatefrequency (e.g., after the carrier center-frequency is down-converted toan intermediate frequency). The location of the filter bank 2000 alongthe receive signal chain can depend on the trade-offs and ability torealize the RU filters of the filter bank 2000.

The example filter bank 2000 includes multiple dedicated bandpassfilters 2002-1 to 2002-37, each having a respective RU gain 2004-1 to2004-37. The example filter bank 2000 includes 37 bandpass filters, eachhaving a respective RU gain; however, any number of multiple bandpassfilters can be used for the filter bank. Having 37 bandpass filtersprovides the filter bank 2000 the ability to be used for an 80 MHzchannel. Two filter banks 2000 can be used in instances where a 160 MHzchannel is used. Each of the bandpass filters 2002-1 to 2002-37 is tunedto a respective bandwidth. FIG. 21 shows an example tuning 2100 of thebandpass filters 2002-1 to 2002-37 shown in FIG. 20. In some instances,each bandpass filter is turned to a bandwidth spanning 26-subcarriers(26×78.125 kHz=1.5625 MHz), as defined by the IEEE 802.11 HE PHY. Asseen in FIG. 21, adjacent RU bandpass filters can have a centerfrequency separation FS, which can be 26-subcarriers (e.g., 1.5625 MHz)in some implementations. The RU gains 2004-1 to 2004-37 can beindependently controlled and can be used to amplify the output of theirrespective bandpass filters 2002-1 to 2002-37. In some instances, therespective RU gains 2004-1 to 2004-37 can be determined based on theHE-STF of the respective HE-PHY frames (e.g., each occupying arespective RU). The output of each of the RU gains 2004-1 to 2004-37 isprovided as an input to a respective power detector 2006-1 to 2006-37.The respective power detectors 2006-1 to 2006-37 determines the power oftheir respective inputs and adjusts the gain of their respective RUgains 2004-1 to 2004-37 such that all RUs have the same power prior tocombining, thereby allowing equalization of the RUs of the receivedUL-OFDMA transmission. In some instances, the respective RU gains 2004-1to 2004-37 are adjusted by the respective power detectors 2006-1 to2006-37 to the highest value without saturating the receive signalchain, while fulfilling the condition that all RUs have the same powerprior to combining. The filter bank 2000 includes a combiner 2008, andthe equalized outputs of the RU gains 2004-1 to 2004-37 are provided tothe combiner 2008. The combiner 2008 sums the outputs of the RU gains2004-1 to 2004-37, and the output of the combiner 2008 is provided as aninput to the remaining receiver components.

The example filter bank 2000 includes a first switch 2010 and a secondswitch 2012, which allow the received signal to be processed by thebandpass filters 2002-1 to 2002-37, the RU gains 2004-1 to 2004-37, thepower detectors 2006-1 to 2006-37, and the combiner 2008. In instanceswhere the RU gains are different, the first switch 2010 is closed andthe second switch 2012 is opened. In instances where the RU gains arethe same, the first switch 2010 is opened and the second switch 2012 isclosed so that the received UL-OFDMA transmission can be passed directlyto the combiner 2008, bypassing the bandpass filters 2002-1 to 2002-37,the RU gains 2004-1 to 2004-37, and the power detectors 2006-1 to2006-37.

Referring back to FIG. 19, operation 1912 (which filters the respectiveHE-PHY frames) includes sub-operations 1914, 1916, and 1918. At 1914, adetermination is made as to whether to implement uniform RU gain orindependent RU gain. In some instances, if the device receiving theUL-OFDMA transmission at 1910 does not have the filter bank 2000,uniform RU gain may be provided, and signals in some RUs may be belowthe noise floor of the device. At 1916, in response to a determinationthat uniform RU gain is to be implemented, the uniform RU gain can bedetermined based on the HE-STF of the combined RUs (e.g., the HE-STF ofthe output of the combiner 2008).

Conversely, if the device receiving the UL-OFDMA transmission at 1910includes the filter bank 2000, independent RU gain may be implemented sothat the RUs of the received UL-OFDMA transmission can be equalized. At1918, in response to a determination that independent RU gain is to beimplemented, the respective RU gains can be determined based on theHE-STF of the respective HE-PHY frames (e.g., each occupying arespective RU).

At 1920, the respective channel responses are computed (e.g., based onthe HE-LTF of the respective HE-PHY frames) and the MAC addresses of thewireless devices transmitting the UL-OFDMA transmission are obtained(e.g., from the respective HE-PHY frames). In some instances, if the“number of HE-LTF symbols and midamble periodicity” and doppler fieldsindicate that midambles are present, there may be more than one channelresponse computed from each of the respective HE-PHY frames (e.g., onechannel response computed from the HE-LTF preamble and another channelresponse computed from the HE-LTF midamble). In some instances, the MACaddresses of the wireless devices may be obtained from the transmittingSTA address (TA) field of the MAC header of the respective HE-PHYframes.

A result of operation 1920 is that the following are associated to eachwireless device (e.g., identified by the AID12 field 1802 of the userinformation list field): the respective RU; the received power level ofthe signal within the respective RU; the channel response(s) computedfrom the HE-LTF of the respective HE-PHY frame; and the wirelessdevice's MAC address.

At 1922, the computed channel responses are validated. For each wirelessdevice identified by the AID12 field 1802 of the user information listfield, the associated channel response is validated (e.g., approved foruse in a motion detection process) if all the following conditions aresatisfied: the received power level indicates the signal is at leastgreater than a minimum threshold; and a valid MAC address was obtainedat 1920. In some instances, the minimum threshold depends on thenoise-floor of the device receiving the UL-OFDMA transmission at 1910,and can be set such that the UL-OFDMA transmission is sufficientlyhigher than the minimum threshold such that a channel response can becomputed. With regards to the validity of the MAC address, the frameheader 914 shown in FIG. 9 includes the transmitter MAC address 918. Asseen in FIG. 9, the frame header 914 is encoded in the MAC layer frame912, which itself is encoded within the PHY data payload 910 of the PHYframe 900. The MAC layer frame 912 includes a 4-byte frame check sum(FCS) 926 that can be used to determine whether an uncorrectable biterror exists in the contents of the MAC layer frame 912. A determinationas to whether a valid MAC addressed was obtained at 1920 can be madebased on the validation of the FCS 926. Operation 1922 generates amotion data set 1924, which can include a set of motion scorescorresponding to the validated channel responses, the RU frequencies andbandwidth, and the identifiers (e.g., MAC addresses) of the wirelessdevices transmitting the UL-OFDMA transmission. The motion data set 1924are provided as in input to a motion detection process to simultaneouslydetect whether motion has occurred in multiple motion detection zones.In some instances, the motion data set 1924 is processed by the motiondetection process to analyze motion within the environment (e.g., tosimultaneously analyze multiple motion detection zones in theenvironment). In some implementations, analyzing motion within theenvironment based on the motion data set 1924 may include determiningwhether motion occurred within the environment. Additionally oralternatively, analyzing motion within the environment based on themotion data set 1924 may include determining the location or intensityof motion performed in the environment.

FIG. 22 is a diagram showing a flowchart for an example process 2200 foranalyzing motion in an environment. The process 2200 can be performed byone (or both) of the listening devices 250-1, 250-2 to analyze motion inan environment (e.g., simultaneously detect whether motion has occurredin respective motion detection zones). Additionally or alternatively,the process 2200 can be performed by one or more of the wireless devices220A, 220B, 220C, 220D to analyze motion in an environment (e.g.,simultaneously detect whether motion has occurred in respective motiondetection zones). The process 2200 may include additional or differentoperations, and the operations shown in FIG. 22 may be performed in theorder shown or in another order. In some cases, one or more of theoperations shown in FIG. 22 are implemented as processes that includemultiple operations, sub-processes for other types of routines. In somecases, operations can be combined, performed in another order, performedin parallel, iterated or otherwise repeated or performed in anothermanner.

At 2202, a downlink high-efficiency PHY (HE-PHY) frame is received. Thedownlink HE-PHY frame can be the DL HE-PHY frame 1106 discussed above inrelation to FIG. 11C. The downlink HE-PHY frame can be transmitted bythe AP 230 to wireless devices 220A, 220B, 220C, 220D residing inside anenvironment. In some instances, the downlink PHY frame is addressed tothe wireless devices 220A, 220B, 220C, 220D.

At 2204, an uplink orthogonal frequency-division multiple access(UL-OFDMA) transmission is received (e.g., in response to the downlinkHE-PHY frame). The UL-OFDMA transmission can be the UL-OFDMAtransmission 1108 discussed above in relation to FIG. 11C. The UL-OFDMAtransmission can be transmitted by the wireless devices 220A, 220B,220C, 220D to the AP 230 in response to the DL HE-PHY frame 1106. TheUL-OFDMA transmission can include uplink HE-PHY frames (e.g., the HE-PHYframes 1108A to 1108N shown in FIG. 11D). As discussed above, the uplinkHE-PHY frames can be simultaneously transmitted on respective resourceunits by the respective wireless communication devices.

At 2206, a motion data set (e.g., the motion data set 1924) is generatedbased on channel responses computed from the UL-OFDMA transmission. Theprocess 1900 described above in relation to FIG. 19 can be used togenerate the motion data set. As an example, the motion data set can begenerated based on channel responses computed from the uplink HE-PHYframes included in the UL-OFDMA transmission. The motion data set caninclude a set of motion scores and identifiers (e.g., MAC addresses) ofthe wireless devices 220A, 220B, 220C, 220D.

At 2208, motion within the environment is analyzed based on the motiondata set. As an example, the motion data set can be used tosimultaneously detect whether motion has occurred in respective motiondetection zones 1006A, 1006B.

Some of the subject matter and operations described in thisspecification can be implemented in digital electronic circuitry, or incomputer software, firmware, or hardware, including the structuresdisclosed in this specification and their structural equivalents, or incombinations of one or more of them. Some of the subject matterdescribed in this specification can be implemented as one or morecomputer programs, i.e., one or more modules of computer programinstructions, encoded on a computer-readable storage medium forexecution by, or to control the operation of, data-processing apparatus.A computer-readable storage medium can be, or can be included in, acomputer-readable storage device, a computer-readable storage substrate,a random or serial access memory array or device, or a combination ofone or more of them. Moreover, while a computer-readable storage mediumis not a propagated signal, a computer-readable storage medium can be asource or destination of computer program instructions encoded in anartificially generated propagated signal. The computer-readable storagemedium can also be, or be included in, one or more separate physicalcomponents or media (e.g., multiple CDs, disks, or other storagedevices). The computer-readable storage medium can include multiplecomputer-readable storage devices. The computer-readable storage devicesmay be co-located (instructions stored in a single storage device), orlocated in different locations (e.g., instructions stored in distributedlocations).

Some of the operations described in this specification can beimplemented as operations performed by a data processing apparatus ondata stored in memory (e.g., on one or more computer-readable storagedevices) or received from other sources. The term “data processingapparatus” encompasses all kinds of apparatus, devices, and machines forprocessing data, including by way of example a programmable processor, acomputer, a system on a chip, or multiple ones, or combinations, of theforegoing. The apparatus can include special purpose logic circuitry,e.g., an FPGA (field programmable gate array) or an ASIC (applicationspecific integrated circuit). The apparatus can also include, inaddition to hardware, code that creates an execution environment for thecomputer program in question, e.g., code that constitutes processorfirmware, a protocol stack, a database management system, an operatingsystem, a cross-platform runtime environment, a virtual machine, or acombination of one or more of them. In some instances, the dataprocessing apparatus includes a set of processors. The set of processorsmay be co-located (e.g., multiple processors in the same computingdevice) or located in different location from one another (e.g.,multiple processors in distributed computing devices). The memorystoring the data executed by the data processing apparatus may beco-located with the data processing apparatus (e.g., a computing deviceexecuting instructions stored in memory of the same computing device),or located in a different location from the data processing apparatus(e.g., a client device executing instructions stored on a serverdevice).

A computer program (also known as a program, software, softwareapplication, instructions, script, or code) can be written in any formof programming language, including compiled or interpreted languages,declarative or procedural languages, and it can be deployed in any form,including as a stand-alone program or as a module, component,subroutine, object, or other unit suitable for use in a computingenvironment. A computer program may, but need not, correspond to a filein a file system. A program can be stored in a portion of a file thatholds other programs or data (e.g., one or more scripts stored in amarkup language document), in a single file dedicated to the program, orin multiple coordinated files (e.g., files that store one or moremodules, sub programs, or portions of code). A computer program can bedeployed to be executed on one computer or on multiple computers thatare located at one site or distributed across multiple sites andinterconnected by a communication network.

Some of the processes and logic flows described in this specificationcan be performed by one or more programmable processors executing one ormore computer programs to perform actions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors 810 suitable for the execution of a computer program include,by way of example, both general and special purpose microprocessors, andprocessors of any kind of digital computer. Generally, a processorreceives instructions and data from a read-only memory or arandom-access memory or both. Elements of a computer can include aprocessor that performs actions in accordance with instructions, and oneor more memory devices that store the instructions and data. A computermay also include, or be operatively coupled to receive data from ortransfer data to, or both, one or more mass storage devices for storingdata, e.g., non-magnetic drives (e.g., a solid-state drive), magneticdisks, magneto optical disks, or optical disks. However, a computer neednot have such devices. Moreover, a computer can be embedded in anotherdevice, e.g., a phone, a tablet computer, an electronic appliance, amobile audio or video player, a game console, a Global PositioningSystem (GPS) receiver, an Internet-of-Things (IoT) device, amachine-to-machine (M2M) sensor or actuator, or a portable storagedevice (e.g., a universal serial bus (USB) flash drive). Devices, e.g.,memory 820, suitable for storing computer program instructions and datainclude all forms of non-volatile memory, media and memory devices,including by way of example semiconductor memory devices (e.g., EPROM,EEPROM, flash memory devices, and others), magnetic disks (e.g.,internal hard disks, removable disks, and others), magneto opticaldisks, and CD ROM and DVD-ROM disks. In some cases, the processor andthe memory can be supplemented by, or incorporated in, special purposelogic circuitry.

To provide for interaction with a user, operations can be implemented ona computer having a display device (e.g., a monitor, or another type ofdisplay device) for displaying information to the user and a keyboardand a pointing device (e.g., a mouse, a trackball, a stylus, a touchsensitive screen, or another type of pointing device) by which the usercan provide input to the computer. Other kinds of devices can be used toprovide for interaction with a user as well; for example, feedbackprovided to the user can be any form of sensory feedback, e.g., visualfeedback, auditory feedback, or tactile feedback; and input from theuser can be received in any form, including acoustic, speech, or tactileinput. In addition, a computer can interact with a user by sendingdocuments to and receiving documents from a device that is used by theuser; for example, by sending web pages to a web browser on a user'sclient device in response to requests received from the web browser.

A computer system may include a single computing device, or multiplecomputers that operate in proximity or generally remote from each otherand typically interact through a communication network. Thecommunication network may include one or more of a local area network(“LAN”) and a wide area network (“WAN”), an inter-network (e.g., theInternet), a network including a satellite link, and peer-to-peernetworks (e.g., ad hoc peer-to-peer networks). A relationship of clientand server may arise by virtue of computer programs running on therespective computers and having a client-server relationship to eachother.

In a general aspect of some of the examples described, motion ispassively detected in an environment using wireless signals.

Example 1: A method, including: at a wireless sensor device that residesoutside an environment, receiving wireless signals transmitted bywireless communication devices that reside inside the environment, eachof the wireless signals being addressed to a respective one of thewireless communication devices. Example 1 includes generating a firstset of motion data including a first set of motion scores and a firstset of link identifiers based on a first subset of the wireless signals,the first set of motion scores based on beamforming reports in the firstsubset of the wireless signals, the first set of link identifiers basedon address information in the first subset of the wireless signals.Example 1 includes generating a second set of motion data including asecond set of motion scores and a second set of link identifiers basedon a second subset of the wireless signals, the second set of motionscores based on channel responses computed from physical (PHY) frames inthe second subset of the wireless signals, the second set of linkidentifiers based on address information in the second subset of thewireless signals. Example 1 includes generating a combined motion dataset including the first and second sets of motion data; and by operationof one or more processors, analyzing motion within the environment basedon the combined data set.

Example 2: The method of Example 1, wherein the wireless signals aretransmitted in a wireless network, and the wireless sensor device is notassociated to the wireless network.

Example 3: The method of Example 2, wherein the wireless networkincludes a wireless local area network, and at least one of the wirelesscommunication devices includes an access point of the wireless localarea network.

Example 4: The method of Example 2, wherein the wireless networkincludes an ad-hoc peer-to-peer wireless network, and the wirelesscommunication devices include peer devices communicatively coupled viathe ad-hoc peer-to-peer wireless network.

Example 5: The method of Example 1, including: determining the first setof link identifiers based on source and destination information in theaddress information in the first subset of the wireless signals; anddetermining the second set of link identifiers based on source anddestination information in the address information in the second subsetof the wireless signals.

Example 6: The method of Example 1, including: generating the first setof motion scores by a first type of motion detection process based onthe beamforming reports in the first subset of the wireless signals; andgenerating the second set of motion scores by a second type of motiondetection process based on the channel responses computed from the PHYframes in the second subset of the wireless signals.

Example 7: The method of Example 1, including computing the channelresponses from preambles or training fields in the PHY frames.

Example 8: The method of Example 1, including: generating a third set ofmotion data including a third set of motion scores and a third set oflink identifiers based on a third subset of the wireless signals; andgenerating the combined data set including the first, second and thirdsets of motion data.

Example 9: The method of Example 1, wherein analyzing motion within theenvironment based on the combined data set includes determining whethermotion occurred within the environment.

Example 10: The method of Example 1, wherein the wireless sensor deviceis a first wireless sensor device, and the method includes: at a secondwireless sensor device that resides outside the environment, receiving asecond set of wireless signals transmitted by one or more of thewireless communication devices that reside inside the environment;generating a third set of motion data including a third set of motionscores and a third set of link identifiers based on the second set ofwireless signals; and generating the combined data set including thefirst, second and third sets of motion data.

Example 11: A system, including: a wireless sensor device residingoutside an environment, the wireless sensor device configured to receivewireless signals transmitted by wireless communication devices residinginside the environment, each of the wireless signals addressed to arespective one of the wireless communication devices. The systemincludes one or more processors configured to: generate a first set ofmotion data including a first set of motion scores and a first set oflink identifiers based on a first subset of the wireless signals, thefirst set of motion scores based on beamforming reports in the firstsubset of the wireless signals, the first set of link identifiers basedon address information in the first subset of the wireless signals;generate a second set of motion data including a second set of motionscores and a second set of link identifiers based on a second subset ofthe wireless signals, the second set of motion scores based on channelresponses computed from physical (PHY) frames in the second subset ofthe wireless signals, the second set of link identifiers based onaddress information in the second subset of the wireless signals;generate a combined motion data set including the first and second setsof motion data; and analyze motion within the environment based on thecombined motion data set.

Example 12: The system of Example 11, wherein the wireless sensor deviceincludes the one or more processors.

Example 13: The system of Example 11, further including a processingdevice residing outside the environment and communicatively coupled tothe wireless sensor device, wherein the one or more processors includes:a first processor configured to generate the first set of motion data,the second set of motion data, and the combined motion data set, thewireless sensor device including the first processor; and a secondprocessor configured to analyze the motion within the environment basedon the combined motion data set, the processing device including thesecond processor.

Example 14: The system of Example 11, further including a processingdevice residing outside the environment and communicatively coupled tothe wireless sensor device, wherein the processing device includes theone or more processors.

Example 15: The system of Example 11, further including the wirelesscommunication devices residing inside the environment.

Example 16: The system of Example 15, wherein the wireless signals aretransmitted in a wireless network, and the wireless sensor device is notassociated to the wireless network.

Example 17: The system of Example 16, wherein the wireless networkincludes an ad-hoc peer-to-peer wireless network, and the wirelesscommunication devices include peer devices communicatively coupledthrough the ad-hoc peer-to-peer wireless network.

Example 18: The system of Example 15, wherein the wireless networkincludes a wireless local area network, and at least one of the wirelesscommunication devices includes an access point of the wireless localarea network.

Example 19: The system of Example 11, wherein the one or more processorsare configured to compute the channel responses from preambles ortraining fields in the PHY frames.

Example 20: The system of Example 11, wherein the one or more processorsare configured to: determine the first set of link identifiers based onsource and destination information in the address information in thefirst subset of the wireless signals; and determine the second set oflink identifiers based on source and destination information in theaddress information in the second subset of the wireless signals.

Example 21: The system of Example 11, wherein the one or more processorsare configured to: generate the first set of motion scores by a firsttype of motion detection process based on the beamforming reports in thefirst subset of the wireless signals; and generate the second set ofmotion scores by a second type of motion detection process based on thechannel responses computed from the PHY frames in the second subset ofthe wireless signals.

Example 22: The system of Example 11, wherein the wireless sensor deviceis a first wireless sensor device, the system further including a secondwireless sensor device residing outside the environment. The secondwireless sensor device is configured to: receive a second set ofwireless signals transmitted by one or more of the wirelesscommunication devices that reside inside the environment; and generate athird set of motion data including a third set of motion scores and athird set of link identifiers based on the second set of wirelesssignals.

Example 23: The system of Example 22, wherein the one or more processorsare configured to generate the combined data set including the first,second and third sets of motion data.

Example 24: The system of Example 23, wherein the first wireless sensordevice includes the one or more processors, and the second wirelesssensor device is configured to transmit the third set of motion data tothe first wireless sensor device.

Example 25: The system of Example 23, further including a processingdevice residing outside the environment and communicatively coupled tothe first and second wireless sensor device, wherein the one or moreprocessors includes: a first processor configured to generate the firstset of motion data, the second set of motion data, and the combinedmotion data set, the first wireless sensor device including the firstprocessor; and a second processor configured to analyze the motionwithin the environment based on the combined motion data set, theprocessing device including the second processor.

Example 26: The system of Example 25, wherein the second wireless sensordevice is configured to transmit the third set of motion data to thefirst wireless sensor device, and the first wireless sensor device isconfigured to transmit the combined motion data set to the processingdevice.

Example 27: A non-transitory computer-readable medium storinginstructions that, when executed by data processing apparatus, cause thedata processing apparatus to perform the operations including: receivingwireless signals transmitted by wireless communication devices thatreside inside an environment, each of the wireless signals addressed toa respective one of the wireless communication devices; generating afirst set of motion scores based on beamforming reports in a firstsubset of the wireless signals; determining a first set of linkidentifiers based on address information in the first subset of thewireless signals; and generating a first set of motion data includingthe first set of motion scores and the first set of link identifiers.The operations include computing channel responses from physical (PHY)frames in a second subset of the wireless signals; generating a secondset of motion scores based on the channel responses; determining asecond set of link identifiers based on address information in thesecond subset of the wireless signals; and generating a second set ofmotion data including the second set of motion scores and the second setof link identifiers. The operations include generating a combined motiondata set including the first and second sets of motion data.

Example 28: The computer-readable medium of Example 27, the operationsfurther including analyzing motion within the environment based on thecombined data set.

Example 29: The computer-readable medium of Example 28, whereinanalyzing motion within the environment based on the combined data setincludes determining whether motion occurred within the environment.

Example 30: The computer-readable medium of Example 27, wherein:determining the first set of link identifiers includes determining thefirst set of link identifiers based on source and destinationinformation in the address information in the first subset of thewireless signals; and determining the second set of link identifiersincludes determining the second set of link identifiers based on sourceand destination information in the address information in the secondsubset of the wireless signals.

Example 31: The computer-readable medium of Example 27, wherein:generating the first set of motion scores includes generating the firstset of motion scores by a first type of motion detection process basedon the beamforming reports in the first subset of the wireless signals;and generating the second set of motion scores includes generating thesecond set of motion scores by a second type of motion detection processbased on the channel responses.

Example 32: The computer-readable medium of Example 27, whereincomputing the channel responses includes computing the channel responsesfrom preambles or training fields in the PHY frames in the second subsetof the wireless signals.

Implementations of the one or more of the above-described examples may,in some cases, include one or more of the following features. The sensordevice is a passive sensor device not associated with the wirelesscommunication network of the remote environment and is in listeningrange of wireless devices transmitting on the wireless communicationnetwork of the remote environment. Identifying the wireless link isbased on source and destination information in the signal including thebeamforming report. One or more beamforming reports are exchanged inresponse to normal communications between a source wirelesscommunication device and a destination wireless communication device.Associating the second channel response information with the wirelesslink includes matching a source identifier of the PHY frame to a sourceidentifier of a wireless link in the remote environment. Combining thefirst channel response information and the second channel responseinformation includes converting the first channel response informationand the second channel response information to respective motion scoresand combining the respective motion scores for each wireless link togenerate a combined motion value indicative of motion. Beamformingreports may include a H-matrix, a V-matrix, or compressed V-matrixformats.

In some implementations, a computer-readable medium stores instructionsthat are operable when executed by a data processing apparatus toperform one or more operations of the above-described examples. In someimplementations, a system (e.g., a wireless communication device,computer system, a combination thereof, or other type of systemcommunicatively coupled to the wireless communication device) includesone or more data processing apparatuses and memory storing instructionsthat are operable when executed by the data processing apparatus toperform one or more operations of the first example.

In an Example 33, a motion detection method includes: receiving adownlink high-efficiency PHY (HE-PHY) frame transmitted by an accesspoint device to wireless communication devices residing inside anenvironment, the downlink HE-PHY frame being addressed to the wirelesscommunication devices. The method further includes receiving an uplinkorthogonal frequency-division multiple access (UL-OFDMA) transmissiontransmitted by the wireless communication devices to the access pointdevice in response to the downlink HE-PHY frame. The UL-OFDMAtransmission includes uplink HE-PHY frames simultaneously transmitted onrespective resource units by the respective wireless communicationdevices. The method additionally includes generating a motion data setincluding a set of motion scores and identifiers of the wirelesscommunication devices based on channel responses computed from theuplink HE-PHY frames. Each channel response is computed from arespective one of the uplink HE-PHY frames. The method includesanalyzing motion within the environment based on the motion data set.

Implementations of Example 33 may include one or more of the followingfeatures. The downlink HE-PHY frame has a first format, and the uplinkHE-PHY frames have a second, different format. The first format is ahigh-efficiency single-user physical layer protocol data unit (HE SUPPDU) format, and the second format is a high-efficiency trigger-basedphysical layer protocol data unit (HE TB PPDU) format. The method canfurther include determining parameters for an uplink transmission basedon the downlink HE-PHY frame, and after applying the parameters to aninterface, receiving the UL-OFDMA transmission by operation of theinterface. The downlink HE-PHY frame includes a trigger frame encoded ina data payload of the downlink HE-PHY frame, and determining theparameters includes determining the parameters based on the triggerframe encoded in the data payload of the downlink HE-PHY frame. Theparameters can include at least one of a total bandwidth of the UL-OFDMAtransmission, a HE-LTF type and guard interval duration of the UL-OFDMAtransmission, information indicative of a midamble in the UL-OFDMAtransmission, a resource unit allocation for the wireless communicationdevices, the identifiers of the wireless communication devices, or atarget received signal strength indicator for the UL-OFDMA transmission.In some instances, the interface resides outside the environment, andreceiving the downlink HE-PHY frame includes receiving the downlinkHE-PHY frame by operation of the interface residing outside theenvironment, and receiving the UL-OFDMA transmission includes receivingthe UL-OFDMA transmission by operation of the interface residing outsidethe environment The identifiers of the wireless communication devicesinclude MAC addresses of the wireless communication devices. The methodcan further include computing the channel responses from High-EfficiencyLong Training Fields (HE-LTFs) in the uplink HE-PHY frames. The channelresponses correspond to respective motion detection zones in theenvironment, and analyzing motion within the environment based on themotion data set includes analyzing motion in the motion detection zonesbased on the motion data set.

In an Example 34, a non-transitory computer-readable medium storesinstructions that are operable when executed by data processingapparatus to perform one or more operations of the Example 33. In anExample 35, a system includes wireless communication devices, awireless-connected device and a computer device configured to performone or more operations of Example 34.

Implementations of Example 35 may include one or more of the followingfeatures. One of the wireless communication devices can be or includethe computer device. One of the wireless communication devices can be orinclude the network-connected device. The computer device can be locatedremote from the wireless communication devices and/or thenetwork-connected device.

While this specification contains many details, these should not beconstrued as limitations on the scope of what may be claimed, but ratheras descriptions of features specific to particular examples. Certainfeatures that are described in this specification in the context ofseparate implementations can also be combined. Conversely, variousfeatures that are described in the context of a single implementationcan also be implemented in multiple embodiments separately or in anysuitable sub-combination.

A number of examples have been described. Nevertheless, it will beunderstood that various modifications can be made. Accordingly, otherexamples are within the scope of the following claims.

What is claimed is:
 1. A motion detection method, comprising: receivinga downlink high-efficiency PHY (HE-PHY) frame transmitted by an accesspoint device to wireless communication devices residing inside anenvironment, the downlink HE-PHY frame being addressed to the wirelesscommunication devices; receiving an uplink orthogonal frequency-divisionmultiple access (UL-OFDMA) transmission transmitted by the wirelesscommunication devices to the access point device in response to thedownlink HE-PHY frame, the UL-OFDMA transmission comprising uplinkHE-PHY frames simultaneously transmitted on respective resource units bythe respective wireless communication devices; generating a motion dataset comprising a set of motion scores and identifiers of the wirelesscommunication devices based on channel responses computed from theuplink HE-PHY frames, each channel response computed from a respectiveone of the uplink HE-PHY frames; and analyzing motion within theenvironment based on the motion data set.
 2. The method of claim 1,wherein the downlink HE-PHY frame has a first format, and the uplinkHE-PHY frames have a second, different format.
 3. The method of claim 2,wherein the first format is a high-efficiency single-user physical layerprotocol data unit (HE SU PPDU) format, and the second format is ahigh-efficiency trigger-based physical layer protocol data unit (HE TBPPDU) format.
 4. The method of claim 1, comprising: determiningparameters for an uplink transmission based on the downlink HE-PHYframe; and after applying the parameters to an interface, receiving theUL-OFDMA transmission by operation of the interface.
 5. The method ofclaim 4, wherein the downlink HE-PHY frame includes a trigger frameencoded in a data payload of the downlink HE-PHY frame, and determiningthe parameters comprises determining the parameters based on the triggerframe encoded in the data payload of the downlink HE-PHY frame.
 6. Themethod of claim 4, wherein the parameters comprise at least one of atotal bandwidth of the UL-OFDMA transmission, a HE-LTF type and guardinterval duration of the UL-OFDMA transmission, information indicativeof a midamble in the UL-OFDMA transmission, a resource unit allocationfor the wireless communication devices, the identifiers of the wirelesscommunication devices, or a target received signal strength indicatorfor the UL-OFDMA transmission.
 7. The method of claim 4, wherein: theinterface resides outside the environment; receiving the downlink HE-PHYframe comprises receiving the downlink HE-PHY frame by operation of theinterface residing outside the environment; and receiving the UL-OFDMAtransmission comprises receiving the UL-OFDMA transmission by operationof the interface residing outside the environment.
 8. The method ofclaim 1, wherein the identifiers of the wireless communication devicescomprise MAC addresses of the wireless communication devices.
 9. Themethod of claim 1, comprising computing the channel responses fromHigh-Efficiency Long Training Fields (HE-LTFs) in the uplink HE-PHYframes.
 10. The method of claim 1, wherein the channel responsescorrespond to respective motion detection zones in the environment, andanalyzing motion within the environment based on the motion data setcomprises analyzing motion in the motion detection zones based on themotion data set.
 11. A system, comprising: a first wirelesscommunication device configured to receive a downlink high-efficiencyPHY (HE-PHY) frame transmitted by an access point device to secondwireless communication devices residing inside an environment, thedownlink PHY frame being addressed to the second wireless communicationdevices; and one or more processors configured to perform operationscomprising: receiving an uplink orthogonal frequency-division multipleaccess (UL-OFDMA) transmission transmitted by the second wirelesscommunication devices to the access point device in response to thedownlink HE-PHY frame, the UL-OFDMA transmission comprising uplinkHE-PHY frames simultaneously transmitted on respective resource units bythe respective second wireless communication devices; generating amotion data set comprising a set of motion scores and identifiers of thewireless communication devices based on channel responses computed fromthe uplink HE-PHY frames, each channel response computed from arespective one of the uplink HE-PHY frames; and analyzing motion withinthe environment based on the motion data set.
 12. The system of claim11, wherein the downlink HE-PHY frame has a first format, and the uplinkHE-PHY frames have a second, different format.
 13. The system of claim12, wherein the first format is a high-efficiency single-user physicallayer protocol data unit (HE SU PPDU) format, and the second format is ahigh-efficiency trigger-based physical layer protocol data unit (HE TBPPDU) format.
 14. The system of claim 11, the operations comprising:determining parameters for an uplink transmission based on the downlinkHE-PHY frame; and after applying the parameters to an interface,receiving the UL-OFDMA transmission by operation of the interface. 15.The system of claim 14, wherein the downlink HE-PHY frame includes atrigger frame encoded in a data payload of the downlink HE-PHY frame,and determining the parameters comprises determining the parametersbased on the trigger frame encoded in the data payload of the downlinkHE-PHY frame.
 16. The system of claim 14, wherein the parameterscomprise at least one of a total bandwidth of the UL-OFDMA transmission,a HE-LTF type and guard interval duration of the UL-OFDMA transmission,information indicative of a midamble in the UL-OFDMA transmission, aresource unit allocation for the wireless communication devices, theidentifiers of the wireless communication devices, or a target receivedsignal strength indicator for the UL-OFDMA transmission.
 17. The systemof claim 14, wherein: the interface resides outside the environment;receiving the downlink HE-PHY frame comprises receiving the downlinkHE-PHY frame by operation of the interface residing outside theenvironment; and receiving the UL-OFDMA transmission comprises receivingthe UL-OFDMA transmission by operation of the interface residing outsidethe environment.
 18. The system of claim 11, wherein the identifiers ofthe wireless communication devices comprise MAC addresses of thewireless communication devices.
 19. The system of claim 11, theoperations comprising computing the channel responses fromHigh-Efficiency Long Training Fields (HE-LTFs) in the uplink HE-PHYframes.
 20. The system of claim 11, wherein the channel responsescorrespond to respective motion detection zones in the environment, andanalyzing motion within the environment based on the motion data setcomprises analyzing motion in the motion detection zones based on themotion data set.
 21. A non-transitory computer-readable medium storinginstructions that, when executed by data processing apparatus, cause thedata processing apparatus to perform the operations comprising:receiving a downlink high-efficiency PHY (HE-PHY) frame transmitted byan access point device to wireless communication devices residing insidean environment, the downlink HE-PHY frame being addressed to thewireless communication devices; receiving an uplink orthogonalfrequency-division multiple access (UL-OFDMA) transmission transmittedby the wireless communication devices to the access point device inresponse to the downlink HE-PHY frame, the UL-OFDMA transmissioncomprising uplink HE-PHY frames simultaneously transmitted on respectiveresource units by the respective wireless communication devices;generating a motion data set comprising a set of motion scores andidentifiers of the wireless communication devices based on channelresponses computed from the uplink HE-PHY frames, each channel responsecomputed from a respective one of the uplink HE-PHY frames; andanalyzing motion within the environment based on the motion data set.22. The non-transitory computer-readable medium of claim 21, wherein thedownlink HE-PHY frame has a first format, and the uplink HE-PHY frameshave a second, different format.
 23. The non-transitorycomputer-readable medium of claim 22, wherein the first format is ahigh-efficiency single-user physical layer protocol data unit (HE SUPPDU) format, and the second format is a high-efficiency trigger-basedphysical layer protocol data unit (HE TB PPDU) format.
 24. Thenon-transitory computer-readable medium of claim 21, the operationscomprising: determining parameters for an uplink transmission based onthe downlink HE-PHY frame; and after applying the parameters to aninterface, receiving the UL-OFDMA transmission by operation of theinterface.
 25. The non-transitory computer-readable medium of claim 24,wherein the downlink HE-PHY frame includes a trigger frame encoded in adata payload of the downlink HE-PHY frame, and determining theparameters comprises determining the parameters based on the triggerframe encoded in the data payload of the downlink HE-PHY frame.
 26. Thenon-transitory computer-readable medium of claim 24, wherein theparameters comprise at least one of a total bandwidth of the UL-OFDMAtransmission, a HE-LTF type and guard interval duration of the UL-OFDMAtransmission, information indicative of a midamble in the UL-OFDMAtransmission, a resource unit allocation for the wireless communicationdevices, the identifiers of the wireless communication devices, or atarget received signal strength indicator for the UL-OFDMA transmission.27. The non-transitory computer-readable medium of claim 24, wherein:the interface resides outside the environment; receiving the downlinkHE-PHY frame comprises receiving the downlink HE-PHY frame by operationof the interface residing outside the environment; and receiving theUL-OFDMA transmission comprises receiving the UL-OFDMA transmission byoperation of the interface residing outside the environment.
 28. Thenon-transitory computer-readable medium of claim 21, wherein theidentifiers of the wireless communication devices comprise MAC addressesof the wireless communication devices.
 29. The non-transitorycomputer-readable medium of claim 1, the operations comprising computingthe channel responses from High-Efficiency Long Training Fields(HE-LTFs) in the uplink HE-PHY frames.
 30. The non-transitorycomputer-readable medium of claim 21, wherein the channel responsescorrespond to respective motion detection zones in the environment, andanalyzing motion within the environment based on the motion data setcomprises analyzing motion in the motion detection zones based on themotion data set.